chore: implemented some hints from CI

Author: petrknap

src/BinariableTrait.php

@@ -4,14 +4,16 @@
 
 namespace PetrKnap\Binary;
 
+/**
+ * @psalm-require-implements BinariableInterface
+ */
 trait BinariableTrait
 {
     /**
      * Unfortunately PHP uses string for binary data, so the magic clashes.
      */
     public function __toString(): string
     {
-        /** @var BinariableInterface $this */
         $binary = $this->toBinary();
         trigger_error(
             'Returned binary string',

src/Coder/Zlib.php

@@ -18,6 +18,10 @@ final class Zlib extends Coder
     public const LEVEL = -1;
     public const MAX_LENGTH = 0;
 
+    private int $encoding;
+    private int $level;
+    private int $maxLength;
+
     public function __construct()
     {
         self::checkRequirements(
@@ -31,10 +35,6 @@ functions: [
         );
     }
 
-    private int $encoding;
-    private int $level;
-    private int $maxLength;
-
     public function encode(string $decoded, ?int $encoding = null, ?int $level = null): string
     {
         $this->encoding = $encoding ?? self::ENCODING;

src/Serializer/SelfSerializerTrait.php

@@ -9,6 +9,8 @@
 /**
  * If your {@see self::__construct()} argument is an instance of {@see SelfSerializerInterface} then
  * accept it as a union type `YourClass|string` and call {@see SelfSerializerInterface::fromBinary()} if it is a string.
+ *
+ * @psalm-require-implements SelfSerializerInterface
  */
 trait SelfSerializerTrait
 {