code: function scale(x, y) {
           return this._set(this.x * x, this.y * (typeof y !== "undefined" ? y : x));
         }
docs: Multiply this vector values by the given scalar
  @name scale
  @memberOf me.Vector2d
  @function
  @param {Number} x
  @param {Number} [y=x]
  @return {me.Vector2d} Reference to this object for method chaining