human
Solve the following python programming problem given the following code:
def registerDeferred(self, event, d) : 
    '
        Register a defer to be fired at the firing of a specific event.

        :param string event: Currently supported values are `connect`. Another
          value may be `_dtor` which will register an event to fire when this
          object has been completely destroyed.

        :param event: The defered to fire when the event succeeds or failes
        :type event: :class:`Deferred`

        If this event has already fired, the deferred will be triggered
        asynchronously.

        Example::

          def on_connect(*args):
              print("I\'m connected")
          def on_connect_err(*args):
              print("Connection failed")

          d = Deferred()
          cb.registerDeferred(\'connect\', d)
          d.addCallback(on_connect)
          d.addErrback(on_connect_err)

        :raise: :exc:`ValueError` if the event name is unrecognized
        ' 
    try : 
        self._evq [event].schedule (event) 
except KeyError : 
        raise ValueError ('No such event type', event) 

    
    

    Fix the buggy line: self._evq [event].schedule (event)
assistant
#Here is Python code to fix the buggy line: self.

self._evq [event].schedule (d)