code: public BoxTransform concatenate(BoxTransform src)
      {
          if (src.isEmpty())
              return this;
          else if (this.isEmpty())
              return src;
          else
          {
              BoxTransform ret = new BoxTransform(this);
              ret.transform = new AffineTransform(transform);
              ret.transform.concatenate(src.transform);
              return ret;
          }
      }
docs: Concatenates another transformation to this transformation.
  @param src
  @return A new concatenated transformation.