/**
  * Guess what property a given element belongs to.
  *
  * @param ClassMetadata $metadata
  * @param string $element
  * @return null|string
  */
 private function guessProperty(ClassMetadata $metadata, $element)
 {
     // Is it the element the actual property
     if ($metadata->hasPropertyMetadata($element)) {
         return $element;
     }
     // Is it a camelized property
     $camelized = $this->camelize($element);
     if ($metadata->hasPropertyMetadata($camelized)) {
         return $camelized;
     }
     return null;
 }