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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 actions(self):
 """The service's actions with their arguments. Returns: list(`Action`):
 A list of Action namedtuples, consisting of action_name (str), in_args (list of Argument namedtuples, consisting of name and argtype), and out_args (ditto). The return value looks like this:: [ Action( name='GetMute', in_args=[ Argument( name='Channel', vartype='string', list=['Master', 'LF', 'RF', 'SpeakerOnly'], range=None ) ], out_args=[ ] ) ] Its string representation will look like this:: GetMute(InstanceID: ui4, Channel: [Master, LF, RF, SpeakerOnly]) \ -> {CurrentMute: boolean} """

        if self._actions is None:
            self._actions = list(self.iter_actions())
        return self._actions