for ( int i = queryStack.size( ) - 1; i >= 0; i-- )
if ( queryStack.getLast( ) instanceof GroupDefinition )
		protected GroupDefinition getCurrentGroup( )		{			if ( queryStack.isEmpty( ) )				return null;			for ( int i = queryStack.size( ) - 1; i >= 0; i-- )			{				if ( queryStack.get( i ) instanceof GroupDefinition )					return (GroupDefinition) queryStack.get( i );			}			return null;		}	