def get_authentication_validation_session(self):
raise Unimplemented()<EOL>
Gets the ``OsidSession`` associated with the ``AuthenticationValidation`` service.

        return:
                (osid.authentication.process.AuthenticationValidationSes
                sion) - an ``AuthenticationValidationSession``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - ``supports_authentication_validation()``
                is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_validation()`` is ``true``.*