/**
  * @covers ::getStorage
  */
 public function testGetStorage()
 {
     $storage = ['FOO' => 'BAR'];
     // Use PHPUnit for mocking, because Prophecy cannot mock methods that return
     // by reference. See \Prophecy\Doubler\Generator\Node::getCode().
     $decorated_form_state = $this->getMock(FormStateInterface::class);
     $decorated_form_state->expects($this->once())->method('getStorage')->willReturn($storage);
     $this->formStateDecoratorBase = new NonAbstractFormStateDecoratorBase($decorated_form_state);
     $this->assertSame($storage, $this->formStateDecoratorBase->getStorage());
 }