python multiprocessing.freeze_support

Running on windows platform, give me an error as below:

File "C:\Python\lib\multiprocessing\forking.py", line 358, in get_command_line
    is not going to be frozen to produce a Windows executable.''')
RuntimeError:
            Attempt to start a new process before the current process
            has finished its bootstrapping phase.

            This probably means that you are on Windows and you have
            forgotten to use the proper idiom in the main module:

                if __name__ == '__main__':
                    freeze_support()
                    ...

            The "freeze_support()" line can be omitted if the program
            is not going to be frozen to produce a Windows executable.

Fix method: add freeze_support

from multiprocessing import freeze_support
if __name__ == '__main__':
    freeze_support()
    a = FSOpsTest
    a.setUpClass()