def METHOD_NAME(self):
    session = FakeSession({})
    session.full_config = {
        'profiles': {'default': {'s3': {'signature_version': 's3v4'}}}}
    session.config = {'s3': {'signature_version': 's3v4'}}
    stream, error_stream, config_get = self.create_command(session)
    rc = config_get(args=['s3'], parsed_globals=None)
    self.assertEqual(rc, 1)
    error_message = error_stream.getvalue()
    expected_message = (
        'varname (s3) must reference a value, not a section or '
        'sub-section.')
    self.assertEqual(error_message, expected_message)
    self.assertEqual(stream.getvalue(), '')