def METHOD_NAME(self, mock_createStageOutCommand):
    mock_createStageOutCommand.return_value = "test"
    result = self.FNALImpl.createStageOutCommand("srm://test", "targetPFN")
    mock_createStageOutCommand.assert_called_with("srm://test", "targetPFN", None)
    self.assertEqual("test", result)
    result = self.FNALImpl.createStageOutCommand("sourcePFN", "srm://test")
    mock_createStageOutCommand.assert_called_with("sourcePFN", "srm://test", None)
    self.assertEqual("test", result)