code: function (x, y, radius, startAngle, endAngle, anticlockwise, addToPath) {
      if (anticlockwise === undefined) anticlockwise = false;
      if (addToPath === undefined) addToPath = false;
      if (!addToPath) this.context.beginPath();
      this.context.arc(x, y, radius, startAngle, endAngle, anticlockwise);
    }
docs: You can either draw the arc alone, therefore addToPath has to be set to false, or
  you can add it to the path
  [https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/arc]
  
  @param {number} x the x coordinate of the arc's center
  @param {number} y the y coordinate of the arc's center
  @param {number} radius the radius of the arc
  @param {number} startAngle The angle at which the arc starts, measured
  clockwise from the positive x axis and expressed in radians.
  @param {number} endAngle The angle at which the arc ends, measured clockwise
  from the positive x axis and expressed in radians.
  @param {?boolean} addToPath (default = false) if the arc is part of a path or is lonely
  @param {?boolean} anticlockwise (default = false) if true, causes the arc to be
  drawn counter-clockwise between the two angles. By default it is drawn clockwise.