def METHOD_NAME(self, mock_copy, mock_exists):
    openmediavault.setenv("OMV_CONFIG_FILE", "abc.conf")
    result = self.command_helper.create_backup()
    self.assertIsNotNone(result)
    self.assertIsNotNone(self.command_helper._backup_path)
    self.assertEqual(result, self.command_helper._backup_path)
    mock_copy.assert_called_with("abc.conf", result)