function createTooltipItem(element) {
	var xScale = element._xScale;
	var yScale = element._yScale || element._scale; // handle radar || polarArea charts
	var index = element._index;
	var datasetIndex = element._datasetIndex;
	var controller = element._chart.getDatasetMeta(datasetIndex).controller;
	var indexScale = controller._getIndexScale();
	var valueScale = controller._getValueScale();

	return {
		xLabel: xScale ? xScale.getLabelForIndex(index, datasetIndex) : '',
		yLabel: yScale ? yScale.getLabelForIndex(index, datasetIndex) : '',
		label: indexScale ? '' + indexScale.getLabelForIndex(index, datasetIndex) : '',
		value: valueScale ? '' + valueScale.getLabelForIndex(index, datasetIndex) : '',
		index: index,
		datasetIndex: datasetIndex,
		x: element._model.x,
		y: element._model.y
	};
}
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