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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 validate_listeners(self):
 """Validates that some listeners are actually registered"""


        if self.exception:
            # pylint: disable=raising-bad-type
            raise self.exception

        listeners = self.__listeners_for_thread
        if not sum(len(l) for l in listeners):
            raise ValueError("No active listeners")