getPixelForTick(index) {
    const ticks = this.ticks;
    if (index < 0 || index > ticks.length - 1) {
      return null;
    }
    return this.getPixelForValue(ticks[index].value);
  }
Returns the location of the tick at the given index
The coordinate (0, 0) is at the upper-left corner of the canvas
@param {number} index
@return {number}