protected function removeUnknownReferences()
	{
		foreach ($this->references as &$references)
		{
			$references = array_intersect_key($references, $this->captures);
		}
	}
protected function removeUnknownReferences()
	{
		foreach ($this->references as &$references)
		{
			$references = array_intersect_key($references, $this->captures);
		}
	}
protected function removeUnknownReferences ( ) { foreach ( $ this -> references as & $ references ) { $ references = array_intersect_key ( $ references , $ this -> captures ) ; } }
Remove references that do not correspond to an existing capture

@return void
Remove references that do not correspond to an existing capture