code: public Class<?> getDispatcherClass (int invCode)
      {
          Object dispatcher = _dispatchers.get(invCode);
          return (dispatcher == null) ? null : dispatcher.getClass();
      }
docs: Get the class that is being used to dispatch the specified invocation code, for
  informational purposes.
  
  @return the Class, or null if no dispatcher is registered with
  the specified code.