public function addCloneableRelation($relation) {
		$relations = $this->getCloneableRelations();
		if (in_array($relation, $relations)) return;
		$relations[] = $relation;
		$this->cloneable_relations = $relations;
	}
public function addCloneableRelation($relation) {
		$relations = $this->getCloneableRelations();
		if (in_array($relation, $relations)) return;
		$relations[] = $relation;
		$this->cloneable_relations = $relations;
	}
public function addCloneableRelation ( $ relation ) { $ relations = $ this -> getCloneableRelations ( ) ; if ( in_array ( $ relation , $ relations ) ) return ; $ relations [ ] = $ relation ; $ this -> cloneable_relations = $ relations ; }
Add a relation to cloneable_relations uniquely

@param  string $relation
@return void
Add a relation to cloneable_relations uniquely