code: function createTooltipItem(element) {
  		var xScale = element._xScale;
  		var yScale = element._yScale || element._scale; // handle radar || polarArea charts
  		var index = element._index,
  			datasetIndex = element._datasetIndex;
  
  		return {
  			xLabel: xScale ? xScale.getLabelForIndex(index, datasetIndex) : '',
  			yLabel: yScale ? yScale.getLabelForIndex(index, datasetIndex) : '',
  			index: index,
  			datasetIndex: datasetIndex,
  			x: element._model.x,
  			y: element._model.y
  		};
  	}
docs: Private helper to create a tooltip item model @param element : the chart element (point, arc, bar) to create the tooltip item for @return : new tooltip item