Improve type signature of AbstractImmutableArrayObject

Author: grebaldi

Classes/Domain/AbstractImmutableArrayObject.php

@@ -7,9 +7,9 @@
 
 /**
  * The abstract class for immutable array objects
- * @template K
+ * @template K of int|string
  * @template V
- * @extends \ArrayObject<int|string,V>
+ * @extends \ArrayObject<K,V>
  */
 abstract class AbstractImmutableArrayObject extends \ArrayObject
 {