bundles/org.eclipse.orion.client.ui/web/orion/explorers/explorerNavHandler.js
function(modelItem) {
			if(!modelItem){
				return null;
			}
			var modelId = this._model.getId(modelItem);
			if(this._dict[modelId]){
				this._dict[modelId].gridChildren = null;
			}
		}
function(modelItem) {
			if(!modelItem){
				return null;
			}
			var modelId = this._model.getId(modelItem);
			if(this._dict[modelId]){
				this._dict[modelId].gridChildren = null;
			}
		}
function ( modelItem ) { if ( ! modelItem ) { return null ; } var modelId = this . _model . getId ( modelItem ) ; if ( this . _dict [ modelId ] ) { this . _dict [ modelId ] . gridChildren = null ; } }
Initialize the grid navigation holder to null.
@param {Object} modelItem The model item object that represent a row.
Initialize the grid navigation holder to null .