code: function _deleteGrid( oGrid, bDestroyLayout ) {
  
  		if (oGrid.__myParentContainerId) {
  			oGrid.__myParentContainerId = undefined;
  		}
  		oGrid.__myParentLayout = undefined;
  
  		if (!bDestroyLayout || !oGrid.getParent()) {
  			// if in real control tree let the ManagedObject logic destroy the children
  			oGrid.destroy();
  		}
  
  	}
docs: /*
  clear internal variables before delete grid