function pushOrConcat(base, toPush) {
	if (toPush) {
		if (helpers$1.isArray(toPush)) {
			// base = base.concat(toPush);
			Array.prototype.push.apply(base, toPush);
		} else {
			base.push(toPush);
		}
	}

	return base;
}
Gets the tooltip position nearest of the item nearest to the event position
@function Chart.Tooltip.positioners.nearest
@param elements {Chart.Element[]} the tooltip elements
@param eventPosition {object} the position of the event in canvas coordinates
@returns {object} the tooltip position