code: function scale(sx) {
      var sy = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : undefined;
  
      if ((0, _utils.isUndefined)(sy)) sy = sx;
      return {
          a: sx, c: 0, e: 0,
          b: 0, d: sy, f: 0
      };
  }
docs: Calculate a scaling matrix
  @param sx Scaling on axis x
  @param [sy = sx] Scaling on axis y (default sx)
  @returns {{a: number, b: number, c: number, e: number, d: number, f: number}} Affine matrix