use "PseudoType"

Author: voku

src/Types/ArrayKey.php

@@ -13,20 +13,28 @@
 
 namespace phpDocumentor\Reflection\Types;
 
+use phpDocumentor\Reflection\PseudoType;
+use phpDocumentor\Reflection\Type;
+
 /**
  * Value Object representing a array-key Type.
  *
  * A array-key Type is the supertype (but not a union) of int and string.
  *
  * @psalm-immutable
  */
-final class ArrayKey extends AggregatedType
+final class ArrayKey extends AggregatedType implements PseudoType
 {
     public function __construct()
     {
         parent::__construct([new String_(), new Integer()], '|');
     }
 
+    public function underlyingType(): Type
+    {
+        return new String_();
+    }
+
     public function __toString(): string
     {
         return 'array-key';

src/Types/ClassString.php

@@ -14,13 +14,15 @@
 namespace phpDocumentor\Reflection\Types;
 
 use phpDocumentor\Reflection\Fqsen;
+use phpDocumentor\Reflection\PseudoType;
+use phpDocumentor\Reflection\Type;
 
 /**
  * Value Object representing the type 'string'.
  *
  * @psalm-immutable
  */
-final class ClassString extends String_
+final class ClassString extends String_ implements PseudoType
 {
     /** @var Fqsen|null */
     private $fqsen;
@@ -33,6 +35,11 @@ public function __construct(?Fqsen $fqsen = null)
         $this->fqsen = $fqsen;
     }
 
+    public function underlyingType(): Type
+    {
+        return new String_();
+    }
+
     /**
      * Returns the FQSEN associated with this object.
      */