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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def call(self, name: str, *args, **kwargs):
        '''Invoke the callback.'''
        if self._event_dispatcher is not None:
            self._event_dispatcher.notify(name, *args, **kwargs)

        if self._callbacks[name]:
            return self._callbacks[name](*args, **kwargs)
        else:
            raise HookDisconnected('No callback is connected.')