protected function handleIsAvailable($handleToTest, Key $existingKey)
 {
     $key = $this->category->getByHandle($handleToTest);
     if (is_object($key)) {
         if ($key->getAttributeKeyID() != $existingKey->getAttributeKeyID()) {
             return false;
         } else {
             return true;
         }
     } else {
         return true;
     }
 }
 public function __construct(Key $attributeKey)
 {
     $this->attributeKey = $attributeKey;
     $this->akID = $attributeKey->getAttributeKeyID();
 }