code: function(padding) {
          return new Rectangle(
              this.origin.x + padding,
              this.origin.y + padding,
              this.extent.x - padding - padding,
              this.extent.y - padding - padding);
      }
docs: _(Formerly: `insetBy`.)_
  @returns {Rectangle} That is enlarged/shrunk by given `padding`.
  @param {number} padding - Amount by which to increase (+) or decrease (-) this rect
  @see The {@link Rectangle#shrinkBy|shrinkBy} method.
  @memberOf Rectangle.prototype