code: function(vInsert, oDomRef) {
  			this.applyPendingGroupItem();
  
  			var iLength = this._aChunk.length;
  			if (!iLength) {
  				return;
  			}
  
  			if (this._oControl.getGrowingDirection() == ListGrowingDirection.Upwards) {
  				this._aChunk.reverse();
  				if (vInsert === true) {
  					vInsert = 0;
  				} else if (typeof vInsert == "number") {
  					vInsert = this._iRenderedDataItems - iLength - vInsert;
  				}
  			}
  
  			oDomRef = oDomRef || this._oContainerDomRef;
  			this._oRM = this._oRM || sap.ui.getCore().createRenderManager();
  
  			for (var i = 0; i < iLength; i++) {
  				this._oRM.renderControl(this._aChunk[i]);
  			}
  
  			this._oRM.flush(oDomRef, false, this._getDomIndex(vInsert));
  			this._aChunk = [];
  		}
docs: render all the collected items in the chunk and flush them into the DOM vInsert whether to append (true) or replace (falsy) or to insert at a certain position (int)