:type name: str
        :param name: The name of the Federated user associated with
                     the credentials.
                     
        :type duration: int
        :param duration: The number of seconds the credentials should
                         remain valid.

        :type policy: str
        :param policy: A JSON policy to associate with these credentials.

def get_federation_token(self, name, duration=None, policy=None):
        """
        :type name: str
        :param name: The name of the Federated user associated with
                     the credentials.
                     
        :type duration: int
        :param duration: The number of seconds the credentials should
                         remain valid.

        :type policy: str
        :param policy: A JSON policy to associate with these credentials.

        """
        params = {'Name' : name}
        if duration:
            params['DurationSeconds'] = duration
        if policy:
            params['Policy'] = policy
        return self.get_object('GetFederationToken', params,
                                FederationToken, verb='POST')