createResponse() ->withAddedHeader('Test', '1') ->withAddedHeader('Test', '2'); $wrapped = new ResponseWrapper($response); $this->assertEquals(['1', '2'], $wrapped->getHeaderAsArray('Test')); } public function testGetHeaderNames(): void { $response = (new ResponseFactory()) ->createResponse() ->withAddedHeader('Test', '1') ->withAddedHeader('Test', '2') ->withAddedHeader('Content-Type', 'application/json'); $wrapped = new ResponseWrapper($response); $this->assertEquals(['Test', 'Content-Type'], $wrapped->getHeaderNames()); } }