code: public void unregisterOperator(final String name) throws Exception
      {
          final String token = name.toLowerCase();
          if (!operatorMap.containsKey(token))
              throw new Exception("unknown operator: " + token);
          operatorMap.remove(token);
      }
docs: <p>
  unregisterOperator.
  </p>
  
  @param name a {@link java.lang.String} object.
  @throws java.lang.Exception if any.