code: function(o, angle) {
              angle = (angle + 360) % 360;
              this.toPolar(o);
              this.y += toRad(angle);
              var p = point.fromPolar(this.x, this.y, o);
              this.x = p.x;
              this.y = p.y;
              return this;
          }
docs: Rotate point by angle around origin o.