import multiprocessing
import sys
import unittest


class MyTestClass(unittest.TestCase):
    # Changing the following to a classmethod or a staticmethod causes the test to succeed
    def _child_process(self):
        sys.exit(0)

    def test_something(self):
        p = multiprocessing.Process(target=self._child_process)
        p.start()   # This fails with a pickle error (different error with unittest and with pytest)
        p.join()


if __name__ == '__main__':
    multiprocessing.set_start_method('spawn')  # in Windows this is the only possibility
    # import pytest
    # pytest.main(args=[__file__])
    unittest.main()