Fix get/setMetadata to create the Map if null

This is needed to handle recreating a node from a quickfile

simulator/src/java/main/ca/nengo/model/impl/AbstractEnsemble.java

@@ -81,7 +81,7 @@ public abstract class AbstractEnsemble implements Ensemble, Probeable, VisiblyMu
 	private Map<String, Origin> myOrigins;
 	private Map<String, EnsembleTermination> myTerminations;
 
-	private transient Map<String, Object> myData;
+	private transient Map<String, Object> myMetadata;
 
 	/**
 	 * Note that setMode(SimulationMode.DEFAULT) is called at construction time.
@@ -117,11 +117,16 @@ private void init() {
         myStateNames = findStateNames(myNodes);
         myListeners = new ArrayList<Listener>(3);
 
-        myData = new LinkedHashMap<String, Object>(2);
 	}
 
-	public Object getMetadata(String key) {return myData.get(key);}
-	public void setMetadata(String key, Object value) {myData.put(key, value);}
+	public Object getMetadata(String key) {
+		if (myMetadata==null) myMetadata = new LinkedHashMap<String, Object>(2);
+		return myMetadata.get(key);
+	}
+	public void setMetadata(String key, Object value) {
+		if (myMetadata==null) myMetadata = new LinkedHashMap<String, Object>(2);		
+		myMetadata.put(key, value);
+	}
 
 
 	/**

simulator/src/java/main/ca/nengo/model/impl/NetworkImpl.java

@@ -115,7 +115,7 @@ public class NetworkImpl implements Network, VisiblyMutable, VisiblyMutable.List
 
     private transient Collection<StepListener> myStepListeners;
 
-	private transient Map<String, Object> myData;
+	private transient Map<String, Object> myMetadata;
 
 
 
@@ -141,9 +141,7 @@ public NetworkImpl() {
 		OrderedExposedOrigins = new LinkedList <Origin> ();
 		OrderedExposedTerminations = new LinkedList <Termination> ();
 
-		myStepListeners = new ArrayList<StepListener>(1);
-
-		myData = new LinkedHashMap<String, Object>(2);		
+		myStepListeners = new ArrayList<StepListener>(1);		
 	}
 
 	/**
@@ -1638,6 +1636,12 @@ public String toPostScript(HashMap<String, Object> scriptData) throws ScriptGenE
 		return py.toString();
 	}
 
-	public Object getMetadata(String key) {return myData.get(key);}
-	public void setMetadata(String key, Object value) {myData.put(key, value);}	
+	public Object getMetadata(String key) {
+		if (myMetadata==null) myMetadata = new LinkedHashMap<String, Object>(2);
+		return myMetadata.get(key);
+	}
+	public void setMetadata(String key, Object value) {
+		if (myMetadata==null) myMetadata = new LinkedHashMap<String, Object>(2);		
+		myMetadata.put(key, value);
+	}
 }