code: function (frameIndex, cx1, cy1, cx2, cy2) {
  		var subdiv1 = 1 / 10/*BEZIER_SEGMENTS*/, subdiv2 = subdiv1 * subdiv1, subdiv3 = subdiv2 * subdiv1;
  		var pre1 = 3 * subdiv1, pre2 = 3 * subdiv2, pre4 = 6 * subdiv2, pre5 = 6 * subdiv3;
  		var tmp1x = -cx1 * 2 + cx2, tmp1y = -cy1 * 2 + cy2, tmp2x = (cx1 - cx2) * 3 + 1, tmp2y = (cy1 - cy2) * 3 + 1;
  		var dfx = cx1 * pre1 + tmp1x * pre2 + tmp2x * subdiv3, dfy = cy1 * pre1 + tmp1y * pre2 + tmp2y * subdiv3;
  		var ddfx = tmp1x * pre4 + tmp2x * pre5, ddfy = tmp1y * pre4 + tmp2y * pre5;
  		var dddfx = tmp2x * pre5, dddfy = tmp2y * pre5;
  
  		var i = frameIndex * 19/*BEZIER_SIZE*/;
  		var curves = this.curves;
  		curves[i++] = 2/*BEZIER*/;
  
  		var x = dfx, y = dfy;
  		for (var n = i + 19/*BEZIER_SIZE*/ - 1; i < n; i += 2) {
  			curves[i] = x;
  			curves[i + 1] = y;
  			dfx += ddfx;
  			dfy += ddfy;
  			ddfx += dddfx;
  			ddfy += dddfy;
  			x += dfx;
  			y += dfy;
  		}
  	}
docs: Sets the control handle positions for an interpolation bezier curve used to transition from this keyframe to the next.
  cx1 and cx2 are from 0 to 1, representing the percent of time between the two keyframes. cy1 and cy2 are the percent of
  the difference between the keyframe's values.