code: public Matrix3 setToTransform (IVector translation, double rotation, IVector scale) {
          double sx = scale.x(), sy = scale.y();
          return setToRotation(rotation).set(m00 * sx, m10 * sy, translation.x(),
                                             m01 * sx, m11 * sy, translation.y(),
                                             0f, 0f, 1f);
      }
docs: Sets this to a matrix that first scales, then rotates, then translates.
  
  @return a reference to this matrix, for chaining.