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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_resource_agent_session(self):
 """Gets the session for retrieving resource agent mappings. return: (osid.resource.ResourceAgentSession) - a ``ResourceAgentSession`` raise: OperationFailed - unable to complete request raise: Unimplemented - ``supports_resource_agent()`` is ``false`` *compliance: optional -- This method must be implemented if ``supports_resource_agent()`` is ``true``.* """

        if not self.supports_resource_agent():
            raise errors.Unimplemented()
        # pylint: disable=no-member
        return sessions.ResourceAgentSession(runtime=self._runtime)