code: function(angle) {
  
              if (!angle) return this.clone();
  
              var theta = toRad(angle);
              var st = abs(sin(theta));
              var ct = abs(cos(theta));
              var w = this.width * ct + this.height * st;
              var h = this.width * st + this.height * ct;
              return new Rect(this.x + (this.width - w) / 2, this.y + (this.height - h) / 2, w, h);
          }
docs: Find my bounding box when I'm rotated with the center of rotation in the center of me. @return r {rectangle} representing a bounding box