API Platform version(s) affected: v1.2.1

Description
i typed a property of a resource like this

  /**
   * @var array<string, string>
   * @ORM\Column(type="json")
   * @Groups({"read", "write"})
   */
  private $answer = [];

and end up with: Class rray<string,string> does not exist
full exception here

How to reproduce
Type a property inside a ApiResource as @var array<string, string> when open Swagger or /api/docs.jsonld