/**
  * {@inheritdoc}
  */
 public function transform(ParameterBag $item)
 {
     $transformer = new EmptyValueToNullTransformer();
     // check for any default values that could be set
     foreach ($this->defaultValues as $key => $value) {
         // only set when it's not existing in the data or has no value
         if (!$item->has($key) || null === $transformer->transform($item->get($key), $key, $item) || $this->overwrite) {
             $item->set($key, $value);
         }
     }
 }
 /**
  * @dataProvider getNonEmptyValues
  */
 public function testNonEmptyValues($value)
 {
     $this->assertNotNull($this->transformer->transform($value));
 }