diff --git a/src/FactorioTools.Serialization/OilField/Steps/GridToBlueprintString.cs b/src/FactorioTools.Serialization/OilField/Steps/GridToBlueprintString.cs
index 1468d229..838e41ff 100644
--- a/src/FactorioTools.Serialization/OilField/Steps/GridToBlueprintString.cs
+++ b/src/FactorioTools.Serialization/OilField/Steps/GridToBlueprintString.cs
@@ -44,8 +44,9 @@ int GetEntityNumber(ElectricPoleCenter pole)
             return entityNumber;
         }
 
-        foreach ((var gridEntity, var location) in context.Grid.EntityToLocation)
+        foreach (var location in context.Grid.EntityLocations.EnumerateItems())
         {
+            var gridEntity = context.Grid[location];
             var position = new Position
             {
                 X = location.X,
diff --git a/src/FactorioTools/OilField/Grid/BeaconCenter.cs b/src/FactorioTools/OilField/Grid/BeaconCenter.cs
index f093df8a..60ee8960 100644
--- a/src/FactorioTools/OilField/Grid/BeaconCenter.cs
+++ b/src/FactorioTools/OilField/Grid/BeaconCenter.cs
@@ -2,6 +2,10 @@
 
 public class BeaconCenter : GridEntity
 {
+    public BeaconCenter(int id) : base(id)
+    {
+    }
+
 #if ENABLE_GRID_TOSTRING
     public override string Label => "B";
 #endif
diff --git a/src/FactorioTools/OilField/Grid/BeaconSide.cs b/src/FactorioTools/OilField/Grid/BeaconSide.cs
index f6b3843f..e798dae5 100644
--- a/src/FactorioTools/OilField/Grid/BeaconSide.cs
+++ b/src/FactorioTools/OilField/Grid/BeaconSide.cs
@@ -2,7 +2,7 @@
 
 public class BeaconSide : GridEntity
 {
-    public BeaconSide(BeaconCenter center)
+    public BeaconSide(int id, BeaconCenter center) : base(id)
     {
         Center = center;
     }
diff --git a/src/FactorioTools/OilField/Grid/ElectricPoleCenter.cs b/src/FactorioTools/OilField/Grid/ElectricPoleCenter.cs
index f28322f3..6cb704ca 100644
--- a/src/FactorioTools/OilField/Grid/ElectricPoleCenter.cs
+++ b/src/FactorioTools/OilField/Grid/ElectricPoleCenter.cs
@@ -6,6 +6,10 @@ public class ElectricPoleCenter : GridEntity
 {
     private readonly HashSet<ElectricPoleCenter> _neighbors = new();
 
+    public ElectricPoleCenter(int id) : base(id)
+    {
+    }
+
 #if ENABLE_GRID_TOSTRING
     public override string Label => "E";
 #endif
diff --git a/src/FactorioTools/OilField/Grid/ElectricPoleSide.cs b/src/FactorioTools/OilField/Grid/ElectricPoleSide.cs
index 2fe55442..b6bbd326 100644
--- a/src/FactorioTools/OilField/Grid/ElectricPoleSide.cs
+++ b/src/FactorioTools/OilField/Grid/ElectricPoleSide.cs
@@ -2,7 +2,7 @@
 
 public class ElectricPoleSide : GridEntity
 {
-    public ElectricPoleSide(ElectricPoleCenter center)
+    public ElectricPoleSide(int id, ElectricPoleCenter center) : base(id)
     {
         Center = center;
     }
diff --git a/src/FactorioTools/OilField/Grid/GridEntity.cs b/src/FactorioTools/OilField/Grid/GridEntity.cs
index 808b9168..e0153839 100644
--- a/src/FactorioTools/OilField/Grid/GridEntity.cs
+++ b/src/FactorioTools/OilField/Grid/GridEntity.cs
@@ -2,10 +2,17 @@
 
 public abstract class GridEntity
 {
+    protected GridEntity(int id)
+    {
+        Id = id;
+    }
+
 #if ENABLE_GRID_TOSTRING
     public abstract string Label { get; }
 #endif
 
+    public int Id { get; }
+
     public virtual void Unlink()
     {
     }
diff --git a/src/FactorioTools/OilField/Grid/Pipe.cs b/src/FactorioTools/OilField/Grid/Pipe.cs
index e66d607d..109eb4c2 100644
--- a/src/FactorioTools/OilField/Grid/Pipe.cs
+++ b/src/FactorioTools/OilField/Grid/Pipe.cs
@@ -2,6 +2,10 @@
 
 public class Pipe : GridEntity
 {
+    public Pipe(int id) : base(id)
+    {
+    }
+
 #if ENABLE_GRID_TOSTRING
     public override string Label => "o";
 #endif
diff --git a/src/FactorioTools/OilField/Grid/PumpjackCenter.cs b/src/FactorioTools/OilField/Grid/PumpjackCenter.cs
index 731abb07..52fc6ddc 100644
--- a/src/FactorioTools/OilField/Grid/PumpjackCenter.cs
+++ b/src/FactorioTools/OilField/Grid/PumpjackCenter.cs
@@ -2,6 +2,10 @@
 
 public class PumpjackCenter : GridEntity
 {
+    public PumpjackCenter(int id) : base(id)
+    {
+    }
+
 #if ENABLE_GRID_TOSTRING
     public override string Label => "J";
 #endif
diff --git a/src/FactorioTools/OilField/Grid/PumpjackSide.cs b/src/FactorioTools/OilField/Grid/PumpjackSide.cs
index b0dc82d1..fc27a723 100644
--- a/src/FactorioTools/OilField/Grid/PumpjackSide.cs
+++ b/src/FactorioTools/OilField/Grid/PumpjackSide.cs
@@ -2,7 +2,7 @@
 
 public class PumpjackSide : GridEntity
 {
-    public PumpjackSide(PumpjackCenter center)
+    public PumpjackSide(int id, PumpjackCenter center) : base(id)
     {
         Center = center;
     }
diff --git a/src/FactorioTools/OilField/Grid/SquareGrid.cs b/src/FactorioTools/OilField/Grid/SquareGrid.cs
index 1daf6a65..b3379664 100644
--- a/src/FactorioTools/OilField/Grid/SquareGrid.cs
+++ b/src/FactorioTools/OilField/Grid/SquareGrid.cs
@@ -13,23 +13,36 @@ public abstract class SquareGrid
     private const string EmptyLabel = ".";
 #endif
 
-    private readonly Dictionary<GridEntity, Location> _entityToLocation;
+    private readonly Dictionary<int, Location> _entityIdToLocation;
+    private readonly ILocationSet _entityLocations;
     private readonly GridEntity?[] _grid;
+    private int _nextId;
 
     public SquareGrid(SquareGrid existing, bool clone)
     {
         Width = existing.Width;
         Height = existing.Height;
-        Middle = new Location(Width / 2, Height / 2);
-        _entityToLocation = clone ? new Dictionary<GridEntity, Location>(existing._entityToLocation) : existing._entityToLocation;
+        Middle = existing.Middle;
 
         if (clone)
         {
+            _entityIdToLocation = new Dictionary<int, Location>(existing._entityIdToLocation);
+#if USE_HASHSETS
+            _entityLocations = new LocationHashSet(existing._entityLocations.Count);
+#else
+            _entityLocations = new LocationIntSet(existing.Width, existing._entityLocations.Count);
+#endif
+            _entityLocations.UnionWith(existing._entityLocations);
+
             _grid = (GridEntity?[])existing._grid.Clone();
+            _nextId = existing._nextId;
         }
         else
         {
+            _entityIdToLocation = existing._entityIdToLocation;
+            _entityLocations = existing._entityLocations;
             _grid = existing._grid;
+            _nextId = existing._nextId;
         }
     }
 
@@ -38,78 +51,94 @@ public SquareGrid(int width, int height)
         Width = width;
         Height = height;
         Middle = new Location(Width / 2, Height / 2);
-        _entityToLocation = new Dictionary<GridEntity, Location>();
+        _entityIdToLocation = new Dictionary<int, Location>();
+#if USE_HASHSETS
+        _entityLocations = new LocationHashSet();
+#else
+        _entityLocations = new LocationIntSet(width);
+#endif
         _grid = new GridEntity?[width * height];
+        _nextId = 1;
     }
 
     public int Width { get; }
     public int Height { get; }
     public Location Middle { get; }
 
-    public GridEntity? this[Location id]
+    public GridEntity? this[Location location]
     {
         get
         {
-            return _grid[GetIndex(id)];
+            return _grid[GetIndex(location)];
         }
     }
 
-    public IReadOnlyDictionary<GridEntity, Location> EntityToLocation => _entityToLocation;
+    public int GetId()
+    {
+        var id = _nextId;
+        _nextId++;
+        return id;
+    }
+
+    public IReadOnlyDictionary<int, Location> EntityIdToLocation => _entityIdToLocation;
+    public ILocationSet EntityLocations => _entityLocations;
 
-    public bool IsEmpty(Location id)
+    public bool IsEmpty(Location location)
     {
-        return _grid[GetIndex(id)] is null;
+        return _grid[GetIndex(location)] is null;
     }
 
-    public void AddEntity(Location id, GridEntity entity)
+    public void AddEntity(Location location, GridEntity entity)
     {
-        var index = GetIndex(id);
+        var index = GetIndex(location);
 
         if (_grid[index] is not null)
         {
-            throw new FactorioToolsException($"There is already an entity at {id}.");
+            throw new FactorioToolsException($"There is already an entity at {location}.");
         }
 
         _grid[index] = entity;
-        _entityToLocation.Add(entity, id);
+        _entityLocations.Add(location);
+        _entityIdToLocation.Add(entity.Id, location);
     }
 
-    public void RemoveEntity(Location id)
+    public void RemoveEntity(Location location)
     {
-        var index = GetIndex(id);
+        var index = GetIndex(location);
         var entity = _grid[index];
         if (entity is not null)
         {
             _grid[index] = null;
-            _entityToLocation.Remove(entity);
+            _entityLocations.Remove(location);
+            _entityIdToLocation.Remove(entity.Id);
             entity.Unlink();
         }
     }
 
-    public bool IsEntityType<T>(Location id) where T : GridEntity
+    public bool IsEntityType<T>(Location location) where T : GridEntity
     {
-        return _grid[GetIndex(id)] is T;
+        return _grid[GetIndex(location)] is T;
     }
 
-    public bool IsInBounds(Location id)
+    public bool IsInBounds(Location location)
     {
-        return id.X >= 0 && id.X < Width && id.Y >= 0 && id.Y < Height;
+        return location.X >= 0 && location.X < Width && location.Y >= 0 && location.Y < Height;
     }
 
-    public abstract void GetNeighbors(Span<Location> neighbors, Location id);
+    public abstract void GetNeighbors(Span<Location> neighbors, Location location);
 
-    public void GetAdjacent(Span<Location> adjacent, Location id)
+    public void GetAdjacent(Span<Location> adjacent, Location location)
     {
-        var a = id.Translate(1, 0);
+        var a = location.Translate(1, 0);
         adjacent[0] = IsInBounds(a) ? a : Location.Invalid;
 
-        var b = id.Translate(0, -1);
+        var b = location.Translate(0, -1);
         adjacent[1] = IsInBounds(b) ? b : Location.Invalid;
 
-        var c = id.Translate(-1, 0);
+        var c = location.Translate(-1, 0);
         adjacent[2] = IsInBounds(c) ? c : Location.Invalid;
 
-        var d = id.Translate(0, 1);
+        var d = location.Translate(0, 1);
         adjacent[3] = IsInBounds(d) ? d : Location.Invalid;
     }
 
@@ -129,7 +158,7 @@ public override string ToString()
 
     public void ToString(StringBuilder builder, int spacing)
     {
-        var maxLabelLength = _entityToLocation.Keys.Max(x => x.Label.Length) + spacing;
+        var maxLabelLength = _entityLocations.EnumerateItems().Max(x => this[x]!.Label.Length) + spacing;
 
         for (var y = 0; y < Height; y++)
         {
@@ -158,7 +187,11 @@ public void ToString(StringBuilder builder, int spacing)
 
     private class Empty : GridEntity
     {
-        public static Empty Instance { get; } = new Empty();
+        public static Empty Instance { get; } = new Empty(0);
+
+        public Empty(int id) : base(id)
+        {
+        }
 
 #if ENABLE_GRID_TOSTRING
         public override string Label => EmptyLabel;
diff --git a/src/FactorioTools/OilField/Grid/TemporaryEntity.cs b/src/FactorioTools/OilField/Grid/TemporaryEntity.cs
index 0281404d..a840431a 100644
--- a/src/FactorioTools/OilField/Grid/TemporaryEntity.cs
+++ b/src/FactorioTools/OilField/Grid/TemporaryEntity.cs
@@ -2,6 +2,10 @@
 
 public class TemporaryEntity : GridEntity
 {
+    public TemporaryEntity(int id) : base(id)
+    {
+    }
+
 #if ENABLE_GRID_TOSTRING
     public override string Label => "?";
 #endif
diff --git a/src/FactorioTools/OilField/Grid/Terminal.cs b/src/FactorioTools/OilField/Grid/Terminal.cs
index 19c52890..bb436756 100644
--- a/src/FactorioTools/OilField/Grid/Terminal.cs
+++ b/src/FactorioTools/OilField/Grid/Terminal.cs
@@ -2,6 +2,10 @@
 
 public class Terminal : Pipe
 {
+    public Terminal(int id) : base(id)
+    {
+    }
+
 #if ENABLE_GRID_TOSTRING
     public override string Label => "+";
 #endif
diff --git a/src/FactorioTools/OilField/Grid/UndergroundPipe.cs b/src/FactorioTools/OilField/Grid/UndergroundPipe.cs
index 67c03df6..84c1c549 100644
--- a/src/FactorioTools/OilField/Grid/UndergroundPipe.cs
+++ b/src/FactorioTools/OilField/Grid/UndergroundPipe.cs
@@ -5,7 +5,7 @@ namespace Knapcode.FactorioTools.OilField;
 
 public class UndergroundPipe : Pipe
 {
-    public UndergroundPipe(Direction direction)
+    public UndergroundPipe(int id, Direction direction) : base(id)
     {
         Direction = direction;
     }
diff --git a/src/FactorioTools/OilField/Helpers.cs b/src/FactorioTools/OilField/Helpers.cs
index a098b483..ad07e0b2 100644
--- a/src/FactorioTools/OilField/Helpers.cs
+++ b/src/FactorioTools/OilField/Helpers.cs
@@ -27,12 +27,12 @@ public static class Helpers
 
     public static PumpjackCenter AddPumpjack(SquareGrid grid, Location center)
     {
-        var centerEntity = new PumpjackCenter();
+        var centerEntity = new PumpjackCenter(grid.GetId());
         for (var x = -1; x <= 1; x++)
         {
             for (var y = -1; y <= 1; y++)
             {
-                GridEntity entity = x != 0 || y != 0 ? new PumpjackSide(centerEntity) : centerEntity;
+                GridEntity entity = x != 0 || y != 0 ? new PumpjackSide(grid.GetId(), centerEntity) : centerEntity;
                 grid.AddEntity(new Location(center.X + x, center.Y + y), entity);
             }
         }
@@ -154,9 +154,9 @@ private static (ILocationDictionary<TInfo> CandidateToInfo, CountedBitArray Cove
         var coveredEntities = new CountedBitArray(recipients.Count);
 
         var providers = context.GetLocationDictionary<TProvider>();
-        foreach (var (entity, location) in context.Grid.EntityToLocation)
+        foreach (var location in context.Grid.EntityLocations.EnumerateItems())
         {
-            var provider = entity as TProvider;
+            var provider = context.Grid[location] as TProvider;
             if (provider is null)
             {
                 continue;
@@ -401,7 +401,7 @@ private static void AddCoveredCenters(
                 }
                 else if (includePumpjacks && entity is PumpjackSide pumpjackSide)
                 {
-                    coveredCenters.Add(grid.EntityToLocation[pumpjackSide.Center]);
+                    coveredCenters.Add(grid.EntityIdToLocation[pumpjackSide.Center.Id]);
                 }
                 else if (includeBeacons && entity is BeaconCenter)
                 {
@@ -409,7 +409,7 @@ private static void AddCoveredCenters(
                 }
                 else if (includeBeacons && entity is BeaconSide beaconSide)
                 {
-                    coveredCenters.Add(grid.EntityToLocation[beaconSide.Center]);
+                    coveredCenters.Add(grid.EntityIdToLocation[beaconSide.Center.Id]);
                 }
             }
         }
@@ -700,8 +700,9 @@ public static (List<ProviderRecipient> PoweredEntities, bool HasBeacons) GetPowe
         var poweredEntities = new List<ProviderRecipient>();
         var hasBeacons = false;
 
-        foreach ((var entity, var location) in context.Grid.EntityToLocation)
+        foreach (var location in context.Grid.EntityLocations.EnumerateItems())
         {
+            var entity = context.Grid[location];
             if (entity is PumpjackCenter)
             {
                 poweredEntities.Add(new ProviderRecipient(location, PumpjackWidth, PumpjackHeight));
@@ -935,8 +936,8 @@ public static void AddBeaconsToGrid(SquareGrid grid, OilFieldOptions options, IE
             AddProviderToGrid(
                 grid,
                 center,
-                new BeaconCenter(),
-                c => new BeaconSide(c),
+                new BeaconCenter(grid.GetId()),
+                c => new BeaconSide(grid.GetId(), c),
                 options.BeaconWidth,
                 options.BeaconHeight);
         }
diff --git a/src/FactorioTools/OilField/Steps/AddElectricPoles.cs b/src/FactorioTools/OilField/Steps/AddElectricPoles.cs
index 265e37ac..80685e00 100644
--- a/src/FactorioTools/OilField/Steps/AddElectricPoles.cs
+++ b/src/FactorioTools/OilField/Steps/AddElectricPoles.cs
@@ -26,7 +26,7 @@ private enum RetryStrategy
                 {
                     if (avoidEntities.Add(location))
                     {
-                        context.Grid.AddEntity(location, new TemporaryEntity());
+                        context.Grid.AddEntity(location, new TemporaryEntity(context.Grid.GetId()));
                     }
                 }
             }   
@@ -150,7 +150,7 @@ private static bool ArePolesConnectedWithout(ILocationDictionary<ElectricPoleCen
                 break;
             }
         }
-        var discovered = new HashSet<ElectricPoleCenter>();
+        var discovered = new HashSet<int>();
 
         while (queue.Count > 0)
         {
@@ -161,7 +161,7 @@ private static bool ArePolesConnectedWithout(ILocationDictionary<ElectricPoleCen
                 continue;
             }
 
-            if (discovered.Add(current))
+            if (discovered.Add(current.Id))
             {
                 foreach (var neighbor in current.Neighbors)
                 {
@@ -604,13 +604,13 @@ private static ElectricPoleCenter AddElectricPole(
         ILocationDictionary<ElectricPoleCenter> electricPoles,
         Location center)
     {
-        var centerEntity = new ElectricPoleCenter();
+        var centerEntity = new ElectricPoleCenter(context.Grid.GetId());
 
         AddProviderToGrid(
             context.Grid,
             center,
             centerEntity,
-            c => new ElectricPoleSide(c),
+            c => new ElectricPoleSide(context.Grid.GetId(), c),
             context.Options.ElectricPoleWidth,
             context.Options.ElectricPoleHeight);
 
@@ -739,7 +739,7 @@ private static void AddSinglePoleForConnection(Context context, ILocationDiction
             var match = false;
             foreach (var neighbor in center.Neighbors)
             {
-                var location = context.Grid.EntityToLocation[neighbor];
+                var location = context.Grid.EntityIdToLocation[neighbor.Id];
                 if (group.Contains(location))
                 {
                     match = true;
@@ -777,14 +777,14 @@ private static List<ILocationSet> GetElectricPoleGroups(Context context, ILocati
             var current = remaining.EnumerateItems().First();
             remaining.Remove(current);
 
-            var entities = new HashSet<ElectricPoleCenter>();
+            var entityIds = new HashSet<int>();
             var explore = new Queue<ElectricPoleCenter>();
             explore.Enqueue(electricPoles[current]);
 
             while (explore.Count > 0)
             {
                 var entity = explore.Dequeue();
-                if (entities.Add(entity))
+                if (entityIds.Add(entity.Id))
                 {
                     foreach (var neighbor in entity.Neighbors)
                     {
@@ -794,9 +794,9 @@ private static List<ILocationSet> GetElectricPoleGroups(Context context, ILocati
             }
 
             var group = context.GetLocationSet(allowEnumerate: true);
-            foreach (var entity in entities)
+            foreach (var entityId in entityIds)
             {
-                var location = context.Grid.EntityToLocation[entity];
+                var location = context.Grid.EntityIdToLocation[entityId];
                 group.Add(location);
             }
 
diff --git a/src/FactorioTools/OilField/Steps/AddPipeEntities.cs b/src/FactorioTools/OilField/Steps/AddPipeEntities.cs
index 3d80ed70..dafa5b0f 100644
--- a/src/FactorioTools/OilField/Steps/AddPipeEntities.cs
+++ b/src/FactorioTools/OilField/Steps/AddPipeEntities.cs
@@ -31,7 +31,7 @@ public static void Execute(
                 foreach ((var location, var direction) in undergroundPipes.EnumeratePairs())
                 {
                     addedPipes.Add(location);
-                    grid.AddEntity(location, new UndergroundPipe(direction));
+                    grid.AddEntity(location, new UndergroundPipe(grid.GetId(), direction));
                 }
             }
 
@@ -46,7 +46,7 @@ public static void Execute(
                 {
                     if (addedPipes.Add(terminals[i].Terminal))
                     {
-                        grid.AddEntity(terminals[i].Terminal, new Terminal());
+                        grid.AddEntity(terminals[i].Terminal, new Terminal(grid.GetId()));
                     }
                 }
             }
@@ -55,7 +55,7 @@ public static void Execute(
             {
                 if (addedPipes.Add(pipe))
                 {
-                    grid.AddEntity(pipe, new Pipe());
+                    grid.AddEntity(pipe, new Pipe(grid.GetId()));
                 }
             }
 
diff --git a/src/FactorioTools/OilField/Steps/InitializeContext.cs b/src/FactorioTools/OilField/Steps/InitializeContext.cs
index 8ef4a895..3ca2e496 100644
--- a/src/FactorioTools/OilField/Steps/InitializeContext.cs
+++ b/src/FactorioTools/OilField/Steps/InitializeContext.cs
@@ -123,8 +123,9 @@ private static int[] GetLocationToAdjacentCount(SquareGrid grid)
         Span<Location> neighbors = new Location[4];
 #endif
 
-        foreach ((var entity, var location) in grid.EntityToLocation)
+        foreach (var location in grid.EntityLocations.EnumerateItems())
         {
+            var entity = grid[location];
             if (entity is not PumpjackSide)
             {
                 continue;
diff --git a/src/FactorioTools/OilField/Steps/PlanBeacons.0.cs b/src/FactorioTools/OilField/Steps/PlanBeacons.0.cs
index 995a6bc8..66026ed5 100644
--- a/src/FactorioTools/OilField/Steps/PlanBeacons.0.cs
+++ b/src/FactorioTools/OilField/Steps/PlanBeacons.0.cs
@@ -10,7 +10,7 @@ public static List<BeaconSolution> Execute(Context context, ILocationSet pipes)
     {
         foreach (var pipe in pipes.EnumerateItems())
         {
-            context.Grid.AddEntity(pipe, new TemporaryEntity());
+            context.Grid.AddEntity(pipe, new TemporaryEntity(context.Grid.GetId()));
         }
 
         var solutions = new List<BeaconSolution>(context.Options.BeaconStrategies.Count);
diff --git a/src/FactorioTools/OilField/Steps/PlanBeacons.1.FBE.cs b/src/FactorioTools/OilField/Steps/PlanBeacons.1.FBE.cs
index e6d42e30..04158cbe 100644
--- a/src/FactorioTools/OilField/Steps/PlanBeacons.1.FBE.cs
+++ b/src/FactorioTools/OilField/Steps/PlanBeacons.1.FBE.cs
@@ -344,12 +344,11 @@ private static ILocationSet GetOccupiedPositions(Context context, List<Area> ent
 
     private static List<Area> GetEntityAreas(Context context)
     {
-        GridEntity pipe = new Pipe();
+        var areas = new List<Area>(context.Grid.EntityLocations.Count);
 
-        var areas = new List<Area>(context.Grid.EntityToLocation.Count);
-
-        foreach (var (entity, location) in context.Grid.EntityToLocation)
+        foreach (var location in context.Grid.EntityLocations.EnumerateItems())
         {
+            var entity = context.Grid[location];
             int width;
             int height;
             bool effect;
diff --git a/src/FactorioTools/OilField/Steps/Validate.cs b/src/FactorioTools/OilField/Steps/Validate.cs
index 053758fd..b62ae18f 100644
--- a/src/FactorioTools/OilField/Steps/Validate.cs
+++ b/src/FactorioTools/OilField/Steps/Validate.cs
@@ -169,8 +169,9 @@ public static void AllEntitiesHavePower(Context context)
             (var poweredEntities, _) = GetPoweredEntities(context);
 
             var electricPoleCenters = new List<Location>();
-            foreach ((var entity, var location) in context.Grid.EntityToLocation)
+            foreach (var location in context.Grid.EntityLocations.EnumerateItems())
             {
+                var entity = context.Grid[location];
                 if (entity is ElectricPoleCenter)
                 {
                     electricPoleCenters.Add(location);
diff --git a/src/Sandbox/Program.cs b/src/Sandbox/Program.cs
index 29db8cc0..42612576 100644
--- a/src/Sandbox/Program.cs
+++ b/src/Sandbox/Program.cs
@@ -12,10 +12,6 @@ private static void Main(string[] args)
         {
             NormalizeBlueprints.Execute(BigListDataPath, SmallListDataPath);
         }
-        else if (args.Length > 0 && args[0] == "measure")
-        {
-            Measure();
-        }
         else if (args.Length > 0 && args[0] == "sample")
         {
             var (context, summary) = Planner.ExecuteSample();
@@ -119,208 +115,4 @@ private static void Sandbox()
             }
         }
     }
-
-    private static void Measure()
-    {
-        var blueprintStringsAll = ParseBlueprint.ReadBlueprintFile(SmallListDataPath).ToArray();
-        var blueprintStrings = blueprintStringsAll;
-        var optionsAll = new[] { OilFieldOptions.ForSmallElectricPole, OilFieldOptions.ForMediumElectricPole, OilFieldOptions.ForSubstation, OilFieldOptions.ForBigElectricPole };
-
-        var outputs = new List<MeasureResult>();
-
-        var addBeaconsAll = new[] { true, false };
-        var overlapBeaconsAll = new[] { true, false };
-
-        foreach (var addBeacons in addBeaconsAll)
-        {
-            var planToWins = new Dictionary<string, int>();
-
-            foreach (var overlapBeacons in overlapBeaconsAll)
-            {
-                if (!addBeacons && !overlapBeacons)
-                {
-                    continue;
-                }
-
-                foreach (var options in optionsAll)
-                {
-                    var pipeSum = 0;
-                    var poleSum = 0;
-                    var beaconSum = 0;
-                    var effectSum = 0;
-                    var blueprintCount = 0;
-                    for (int i = 0; i < blueprintStrings.Length; i++)
-                    {
-                        Console.WriteLine("Index " + i);
-                        string? blueprintString = blueprintStrings[i];
-                        var inputBlueprint = ParseBlueprint.Execute(blueprintString);
-
-                        options.AddBeacons = addBeacons;
-                        options.UseUndergroundPipes = options.AddBeacons;
-                        options.OptimizePipes = true;
-                        options.ValidateSolution = false;
-                        options.OverlapBeacons = overlapBeacons;
-
-                        var (context, summary) = Planner.Execute(options, inputBlueprint);
-
-                        var pipeCount = context.Grid.EntityToLocation.Keys.OfType<Pipe>().Count();
-                        var poleCount = context.Grid.EntityToLocation.Keys.OfType<ElectricPoleCenter>().Count();
-                        var beaconCount = context.Grid.EntityToLocation.Keys.OfType<BeaconCenter>().Count();
-                        var effectCount = summary.SelectedPlans[0].BeaconEffectCount;
-
-                        foreach (var plan in summary.SelectedPlans.Concat(summary.AlternatePlans).Select(p => p.ToString()))
-                        {
-                            if (!planToWins.TryGetValue(plan, out var count))
-                            {
-                                planToWins.Add(plan, 1);
-                            }
-                            else
-                            {
-                                planToWins[plan] = count + 1;
-                            }
-                        }
-
-                        Console.WriteLine($"{pipeCount},{poleCount},{beaconCount},{effectCount}");
-
-                        pipeSum += pipeCount;
-                        poleSum += poleCount;
-                        beaconSum += beaconCount;
-                        effectSum += effectCount;
-                        blueprintCount++;
-                    }
-
-                    outputs.Add(new MeasureResult(
-                        options.ElectricPoleEntityName,
-                        options.AddBeacons,
-                        options.AddBeacons ? (options.OverlapBeacons ? "yes" : "no") : "N/A",
-                        pipeSum * 1.0 / blueprintCount,
-                        poleSum * 1.0 / blueprintCount,
-                        beaconSum * 1.0 / blueprintCount,
-                        effectSum * 1.0 / blueprintCount));
-                }
-            }
-
-            Console.WriteLine();
-            var maxWidth = planToWins.Keys.Max(p => p.Length);
-            foreach ((var plan, var wins) in planToWins.OrderBy(p => p.Value))
-            {
-                Console.WriteLine($"{plan.PadLeft(maxWidth)} : {wins}");
-            }
-            Console.WriteLine();
-        }
-
-        var tableBuilder = new TableBuilder();
-        tableBuilder.AddColumns(
-            "Electric pole",
-            "Add beacons",
-            "Overlap beacons",
-            "Pipe count",
-            "Pole count",
-            "Beacon count",
-            "Effect count");
-
-        foreach (var output in outputs)
-        {
-            tableBuilder.AddRow(
-                output.ElectricPoleEntityName,
-                output.AddBeacons ? "yes" : "no",
-                output.OverlapBeacons,
-                output.PipeCount,
-                output.PoleCount,
-                output.BeaconCount,
-                output.EffectCount);
-        }
-
-        Console.WriteLine(tableBuilder.Build());
-    }
-
-    public class TableBuilder
-    {
-        private readonly List<string> _columns = new();
-        private readonly List<IEnumerable<object>> _rows = new();
-
-        public void AddColumn(string label)
-        {
-            _columns.Add(label);
-        }
-
-        public void AddColumns(params string[] labels)
-        {
-            for (var i = 0; i < labels.Length; i++)
-            {
-                AddColumn(labels[i]);
-            }
-        }
-
-        public void AddRow(params object[] row)
-        {
-            _rows.Add(row);
-        }
-
-        public void AddRow<T>(IEnumerable<T> row)
-        {
-            _rows.Add(row.Cast<object>());
-        }
-
-        public string Build()
-        {
-            var rows = _rows.Select(x => x.ToList()).ToList();
-            var columnCount = Math.Max(_columns.Count, rows.Select(x => x.Count).DefaultIfEmpty(0).Max());
-
-            var maxWidths = new int[columnCount];
-            var columnHeadings = new string[columnCount];
-
-            for (var i = 0; i < columnCount; i++)
-            {
-                columnHeadings[i] = _columns.ElementAtOrDefault(i) ?? $"(column {i + 1})";
-                maxWidths[i] = _rows
-                    .Select(x => x.ElementAtOrDefault(i)?.ToString() ?? string.Empty)
-                    .Append(columnHeadings[i])
-                    .Max(x => x.Length);
-            }
-
-            var builder = new StringBuilder();
-            AppendRow(builder, columnCount, maxWidths, i => columnHeadings[i]);
-            AppendRow(builder, columnCount, maxWidths, i => new string('-', maxWidths[i]));
-            foreach (var row in rows)
-            {
-                AppendRow(builder, columnCount, maxWidths, i => row[i]?.ToString() ?? string.Empty);
-            }
-
-            return builder.ToString();
-        }
-
-        private static void AppendRow(StringBuilder builder, int columnCount, int[] maxWidths, Func<int, string> getValue)
-        {
-            for (var i = 0; i < columnCount; i++)
-            {
-                if (i == 0)
-                {
-                    builder.Append("| ");
-                }
-                else
-                {
-                    builder.Append(" | ");
-                }
-
-                builder.Append(getValue(i).PadRight(maxWidths[i]));
-
-                if (i ==  columnCount - 1)
-                {
-                    builder.Append(" |");
-                }
-            }
-
-            builder.AppendLine();
-        }
-    }
-
-    private record MeasureResult(
-        string ElectricPoleEntityName,
-        bool AddBeacons,
-        string OverlapBeacons,
-        double PipeCount,
-        double PoleCount,
-        double BeaconCount,
-        double EffectCount);
 }
\ No newline at end of file
diff --git a/test/FactorioTools.Test/OilField/BaseFacts.cs b/test/FactorioTools.Test/OilField/BaseFacts.cs
index f5ff2d6b..fe9b7392 100644
--- a/test/FactorioTools.Test/OilField/BaseFacts.cs
+++ b/test/FactorioTools.Test/OilField/BaseFacts.cs
@@ -7,13 +7,13 @@ public abstract class BaseFacts
 {
     public static ElectricPoleCenter AddElectricPole(Context context, Location center)
     {
-        var entity = new ElectricPoleCenter();
+        var entity = new ElectricPoleCenter(context.Grid.GetId());
 
         AddProviderToGrid(
             context.Grid,
             center,
             entity,
-            c => new ElectricPoleSide(c),
+            c => new ElectricPoleSide(context.Grid.GetId(), c),
             providerWidth: context.Options.ElectricPoleWidth,
             providerHeight: context.Options.ElectricPoleHeight);
 
@@ -22,13 +22,13 @@ public static ElectricPoleCenter AddElectricPole(Context context, Location cente
 
     public static BeaconCenter AddBeacon(Context context, Location center)
     {
-        var entity = new BeaconCenter();
+        var entity = new BeaconCenter(context.Grid.GetId());
 
         AddProviderToGrid(
             context.Grid,
             center,
             entity,
-            c => new BeaconSide(c),
+            c => new BeaconSide(context.Grid.GetId(),c),
             providerWidth: context.Options.BeaconWidth,
             providerHeight: context.Options.BeaconHeight);
 
@@ -53,7 +53,7 @@ public static PumpjackCenter AddPumpjack(Context context, Location center, Direc
             if (context.Grid[selectedTerminal.Terminal] is Pipe)
             {
                 context.Grid.RemoveEntity(selectedTerminal.Terminal);
-                context.Grid.AddEntity(selectedTerminal.Terminal, new Terminal());
+                context.Grid.AddEntity(selectedTerminal.Terminal, new Terminal(context.Grid.GetId()));
             }
         }
 
diff --git a/test/FactorioTools.Test/OilField/Score.cs b/test/FactorioTools.Test/OilField/Score.cs
index 6b5ac707..a1e854c2 100644
--- a/test/FactorioTools.Test/OilField/Score.cs
+++ b/test/FactorioTools.Test/OilField/Score.cs
@@ -49,7 +49,7 @@ public async Task HasExpectedScore()
                     summary.SelectedPlans[0].BeaconCount,
                     PipeCountWithUnderground = summary.SelectedPlans[0].PipeCount,
                     summary.SelectedPlans[0].PipeCountWithoutUnderground,
-                    PoleCount = context.Grid.EntityToLocation.Keys.OfType<ElectricPoleCenter>().Count(),
+                    PoleCount = context.Grid.GetEntities().OfType<ElectricPoleCenter>().Count(),
                 };
             });
 
diff --git a/test/FactorioTools.Test/OilField/Steps/HelpersTest.cs b/test/FactorioTools.Test/OilField/Steps/HelpersTest.cs
index 5e9d4dfc..91ef7745 100644
--- a/test/FactorioTools.Test/OilField/Steps/HelpersTest.cs
+++ b/test/FactorioTools.Test/OilField/Steps/HelpersTest.cs
@@ -303,7 +303,7 @@ public void Substation_RemoveUnused()
             
             // Visualizer.Show(context.Grid, candidateToCovered.Keys.Select(c => (DelaunatorSharp.IPoint)new DelaunatorSharp.Point(c.X, c.Y)), Array.Empty<DelaunatorSharp.IEdge>());
 
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.True(e is PumpjackSide || e is PumpjackCenter));
+            Assert.All(context.Grid.GetEntities(), e => Assert.True(e is PumpjackSide || e is PumpjackCenter));
             Assert.Equal(0, providers.Count);
 
             // These are positions that should become candidates after unused substations are removed.
diff --git a/test/FactorioTools.Test/OilField/Steps/PlanUndergroundPipesTest.cs b/test/FactorioTools.Test/OilField/Steps/PlanUndergroundPipesTest.cs
index fb0f894d..ba64e136 100644
--- a/test/FactorioTools.Test/OilField/Steps/PlanUndergroundPipesTest.cs
+++ b/test/FactorioTools.Test/OilField/Steps/PlanUndergroundPipesTest.cs
@@ -40,8 +40,8 @@ public void Horizontal_OneRun(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(2, context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsType<UndergroundPipe>(e));
+            Assert.Equal(2, context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsType<UndergroundPipe>(e));
 
             var left = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Left, left.Direction);
@@ -61,10 +61,10 @@ public void Horizontal_OneRun_WithExtra(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(2 + (length - 11), context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
-            Assert.Equal(2, context.Grid.EntityToLocation.Keys.Count(e => e is UndergroundPipe));
-            Assert.Equal(2 + (length - 11), context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(2 + (length - 11), context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(2, context.Grid.GetEntities().Count(e => e is UndergroundPipe));
+            Assert.Equal(2 + (length - 11), context.Grid.GetEntities().Count(e => e is Pipe));
 
             var left = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Left, left.Direction);
@@ -92,9 +92,9 @@ public void Horizontal_TwoRuns(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(4, context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
-            Assert.Equal(4, context.Grid.EntityToLocation.Keys.Count(e => e is UndergroundPipe));
+            Assert.Equal(4, context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(4, context.Grid.GetEntities().Count(e => e is UndergroundPipe));
 
             var leftA = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Left, leftA.Direction);
@@ -119,10 +119,10 @@ public void Horizontal_TwoRuns_WithExtra(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(4 + (length - 22), context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
-            Assert.Equal(4, context.Grid.EntityToLocation.Keys.Count(e => e is UndergroundPipe));
-            Assert.Equal(4 + (length - 22), context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(4 + (length - 22), context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(4, context.Grid.GetEntities().Count(e => e is UndergroundPipe));
+            Assert.Equal(4 + (length - 22), context.Grid.GetEntities().Count(e => e is Pipe));
 
             var leftA = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Left, leftA.Direction);
@@ -171,8 +171,8 @@ public void Vertical_OneRun(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(2, context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsType<UndergroundPipe>(e));
+            Assert.Equal(2, context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsType<UndergroundPipe>(e));
 
             var up = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Up, up.Direction);
@@ -192,10 +192,10 @@ public void Vertical_OneRun_WithExtra(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(2 + (length - 11), context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
-            Assert.Equal(2, context.Grid.EntityToLocation.Keys.Count(e => e is UndergroundPipe));
-            Assert.Equal(2 + (length - 11), context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(2 + (length - 11), context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(2, context.Grid.GetEntities().Count(e => e is UndergroundPipe));
+            Assert.Equal(2 + (length - 11), context.Grid.GetEntities().Count(e => e is Pipe));
 
             var up = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Up, up.Direction);
@@ -223,9 +223,9 @@ public void Vertical_TwoRuns(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(4, context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
-            Assert.Equal(4, context.Grid.EntityToLocation.Keys.Count(e => e is UndergroundPipe));
+            Assert.Equal(4, context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(4, context.Grid.GetEntities().Count(e => e is UndergroundPipe));
 
             var upA = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Up, upA.Direction);
@@ -249,10 +249,10 @@ public void Vertical_TwoRuns_WithExtra(int length)
 
             Run(context, pipes);
 
-            Assert.Equal(4 + (length - 22), context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
-            Assert.Equal(4, context.Grid.EntityToLocation.Keys.Count(e => e is UndergroundPipe));
-            Assert.Equal(4 + (length - 22), context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(4 + (length - 22), context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(4, context.Grid.GetEntities().Count(e => e is UndergroundPipe));
+            Assert.Equal(4 + (length - 22), context.Grid.GetEntities().Count(e => e is Pipe));
 
             var upA = Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 1)]);
             Assert.Equal(Direction.Up, upA.Direction);
@@ -277,8 +277,8 @@ public void Intersection_Plus()
 
             Run(context, pipes);
 
-            Assert.Equal(9, context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(9, context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
 
             Assert.Equal(Direction.Left, Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 6)]).Direction);
             Assert.Equal(Direction.Right, Assert.IsType<UndergroundPipe>(context.Grid[new Location(5, 6)]).Direction);
@@ -305,8 +305,8 @@ public void Intersection_T()
 
             Run(context, pipes);
 
-            Assert.Equal(7, context.Grid.EntityToLocation.Count);
-            Assert.All(context.Grid.EntityToLocation.Keys, e => Assert.IsAssignableFrom<Pipe>(e));
+            Assert.Equal(7, context.Grid.EntityLocations.Count);
+            Assert.All(context.Grid.GetEntities(), e => Assert.IsAssignableFrom<Pipe>(e));
 
             Assert.Equal(Direction.Left, Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 6)]).Direction);
             Assert.Equal(Direction.Right, Assert.IsType<UndergroundPipe>(context.Grid[new Location(10, 6)]).Direction);
@@ -330,7 +330,7 @@ public void RunIsInterruptedByTerminal()
 
             Run(context, pipes);
 
-            Assert.Equal(5, context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(5, context.Grid.GetEntities().Count(e => e is Pipe));
 
             Assert.Equal(Direction.Left, Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 4)]).Direction);
             Assert.Equal(Direction.Right, Assert.IsType<UndergroundPipe>(context.Grid[new Location(5, 4)]).Direction);
@@ -352,7 +352,7 @@ public void RunIsAdjacentToTerminal()
 
             Run(context, pipes);
 
-            Assert.Equal(6, context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(6, context.Grid.GetEntities().Count(e => e is Pipe));
 
             Assert.Equal(Direction.Left, Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 4)]).Direction);
             Assert.Equal(Direction.Right, Assert.IsType<UndergroundPipe>(context.Grid[new Location(4, 4)]).Direction);
@@ -374,7 +374,7 @@ public void RunEndsWithTerminal()
 
             Run(context, pipes);
 
-            Assert.Equal(2, context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(2, context.Grid.GetEntities().Count(e => e is Pipe));
 
             Assert.Equal(Direction.Left, Assert.IsType<UndergroundPipe>(context.Grid[new Location(1, 3)]).Direction);
             Assert.Equal(Direction.Right, Assert.IsType<UndergroundPipe>(context.Grid[new Location(5, 3)]).Direction);
@@ -390,7 +390,7 @@ public void RunStartsWithTerminal()
 
             Run(context, pipes);
 
-            Assert.Equal(2, context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(2, context.Grid.GetEntities().Count(e => e is Pipe));
 
             Assert.Equal(Direction.Left, Assert.IsType<UndergroundPipe>(context.Grid[new Location(4, 1)]).Direction);
             Assert.Equal(Direction.Right, Assert.IsType<UndergroundPipe>(context.Grid[new Location(8, 1)]).Direction);
@@ -407,7 +407,7 @@ public void RunStartsAndEndsWithTerminal()
 
             Run(context, pipes);
 
-            Assert.Equal(2, context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(2, context.Grid.GetEntities().Count(e => e is Pipe));
 
             Assert.Equal(Direction.Left, Assert.IsType<UndergroundPipe>(context.Grid[new Location(4, 3)]).Direction);
             Assert.Equal(Direction.Right, Assert.IsType<UndergroundPipe>(context.Grid[new Location(8, 3)]).Direction);
@@ -418,7 +418,7 @@ private static void Run(Context context, List<Location> pipes)
             var locationSet = pipes.ToReadOnlySet(context, allowEnumerate: true);
             var undergroundPipes = PlanUndergroundPipes.Execute(context, locationSet);
 
-            Assert.Equal(0, context.Grid.EntityToLocation.Keys.Count(e => e is Pipe));
+            Assert.Equal(0, context.Grid.GetEntities().Count(e => e is Pipe));
             Assert.All(undergroundPipes.Keys, p => Assert.Contains(p, pipes));
 
             AddPipeEntities.Execute(context, locationSet, undergroundPipes);
diff --git a/test/FactorioTools.Test/SetVerifySettings.cs b/test/FactorioTools.Test/SetVerifySettings.cs
index 386eae4e..5c197721 100644
--- a/test/FactorioTools.Test/SetVerifySettings.cs
+++ b/test/FactorioTools.Test/SetVerifySettings.cs
@@ -1,4 +1,5 @@
 using System.Runtime.CompilerServices;
+using Knapcode.FactorioTools.OilField;
 
 namespace Knapcode.FactorioTools;
 
@@ -11,3 +12,14 @@ public static void Initialize()
         VerifierSettings.AutoVerify(includeBuildServer: false);
     }
 }
+
+public static class ExtensionMethods
+{
+    public static IEnumerable<GridEntity> GetEntities(this SquareGrid grid)
+    {
+        foreach (var location in grid.EntityLocations.EnumerateItems())
+        {
+            yield return grid[location]!;
+        }
+    }
+}
\ No newline at end of file