draw(ctx, x, y, selected, hover, values) {
    return this._drawShape(ctx, "diamond", 4, x, y, selected, hover, values);
  }
@param {CanvasRenderingContext2D} ctx
@param {number} x width
@param {number} y height
@param {boolean} selected
@param {boolean} hover
@param {ArrowOptions} values
@returns {object} Callbacks to draw later on higher layers.