/**
  * Sets parent channel
  *
  * @param CircularReferenceEntity $parent parent
  * @return CircularReferenceEntity
  */
 public function setParent(CircularReferenceEntity $parent = null)
 {
     if ($this->Parent !== $parent) {
         if (!is_null($this->Parent)) {
             $this->Parent->removeChild($this);
         }
         if (!is_null($parent)) {
             $parent->addChild($this);
         }
         $this->Parent = $parent;
     }
     return $this;
 }