docs: public AffineTransform transform() {
      if (isSet(Flag.XFDIRTY)) {
        float sina = FloatMath.sin(rotation), cosa = FloatMath.cos(rotation);
        float m00 =  cosa * scaleX, m01 = sina * scaleX;
        float m10 = -sina * scaleY, m11 = cosa * scaleY;
        float tx = transform.tx(), ty = transform.ty();
        transform.setTransform(m00, m01, m10, m11, tx, ty);
        setFlag(Flag.XFDIRTY, false);
      }
      return transform;
    }