code: function addNavGrid(navDict, rowModel, domNode) {
  		if(!navDict){
  			return;
  		}
  		var navHolder = navDict.getGridNavHolder(rowModel, true);
  		if(navHolder){
  			generateNavGrid(navHolder, domNode);
  		}
  	}
docs: Add a grid navigation item to the navigation dictionary. A row navigation model normally comes from any node in a {treeModelIterator}.
  The .gridChildren property will be lazily created on the row model as an array where all the grid navigation items live.
  
  @param {ExplorerNavDict} navDict the dictionary that holds the info of all navigation info from model id.
  @param {object} rowModel the row model from the {treeModelIterator}.
  @param {Element} element the html dom element representing a grid. Normally left or right arrow keys on the current row highlight the dom element.
  When a grid is rendered, the caller has to decide what dom element can be passed.