Better handle unittest module

[MikhailArkhipov]

# https://docs.python.org/3/library/unittest.html#module-unittest
import unittest

class Simple(unittest.TestCase):
    def test_success(self):
        self.assertEqual()  # Funky: docs don't' show method arguments.

    def test_exception(self):
        with self.assertRaises(Exception) as em:
            raise Exception
        exc = em.exception # Fails: doesn't infer `exception`.
        with self.assertRaisesRegex(ValueError, 'literal') as em2:
            int('XYZ')
        em2.exception

    def test_logging(self):
        with self.assertLogs('foo', level='INFO') as cm:
            pass
        cm.output # Fails: doesn't infer `output`.

    def test_subtests(self):
        for i in range(0, 6):
            with self.subTest(i=i):
                self.assertEqual(i % 2, 0)



def load_tests(loader, tests, pattern):
    suite = unittest.TestSuite()
    for test_class in test_cases:
        test = loader.loadTestsfromTestCase(test_class)
        suite.addTests(tests)
    return suite


if __name__ == '__main__':
    unittest.main()

[MikhailArkhipov]

Works well with typeshed.