code: public void showRPN(final StringBuilder sb) throws Exception
      {
          for (final EquPart part : rpn)
          {
              sb.append(part.toString());
              sb.append("\n");
          }
      }
docs: <p>
  showRPN.
  </p>
  
  @param sb a {@link java.lang.StringBuilder} object.
  @throws java.lang.Exception if any.