Seeing the following program, in the second assertRaises(), function "test_invalid_adpcm_state()"  is recursively called. Then a fatal Python error shows up and the Python interpreter crashes. 

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import unittest
import audioop

class TestAudioop(unittest.TestCase):
         pass

def test_invalid_adpcm_state():
         TestAudioop.assertRaises(TypeError, audioop.lin2adpcm, b'\x00', 1, 555)
         TestAudioop.assertRaises(test_invalid_adpcm_state(), audioop.adpcm2lin, b'\x00', 1, (0, (- 1)))

TestAudioop = TestAudioop()
test_invalid_adpcm_state()

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System Info: Ubuntu 16.04
Python Version:  Python 3.9.1