code: def register(cls, name):
          
  
          def decorate(klazz):
              """ Decorator. """
              if name in cls._events:
                  raise GerritError("Duplicate event: %s" % name)
              cls._events[name] = [klazz.__module__, klazz.__name__]
              klazz.name = name
              return klazz
          return decorate
docs: Decorator to register the event identified by `name`.
  
          Return the decorated class.
  
          Raise GerritError if the event is already registered.