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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 get_public_methods(self):
 """ return a list of methods on this class which should be exposed in the rex API. """

        return self.get_action_methods() + [
            ('getenv', self.getenv),
            ('expandvars', self.expandvars),
            ('defined', self.defined),
            ('undefined', self.undefined)]