DygraphOps.dispatchMouseDown(g, xRange[0], yRange[0]);
DygraphOps.dispatchMouseMove(g, xRange[1], yRange[0]); // this is really necessary.
DygraphOps.dispatchMouseUp(g, xRange[1], yRange[0]);
DygraphOps.dispatchMouseDown(g, xRange[0], yRange[0]);
DygraphOps.dispatchMouseMove(g, xRange[1], yRange[0]); // this is really necessary.
DygraphOps.dispatchMouseUp(g, xRange[1], yRange[0]);