def __init__(self, testCase, expected):
        """
        @param testCase: The L{TestCase} instance which is used to raise a
            test-failing exception when that is necessary.

        @param expected: The exception type expected to be raised.
        """
        self._testCase = testCase
        self._expected = expected
        self._returnValue = None
        try:
            self._expectedName = self._expected.__name__
        except AttributeError:
            self._expectedName = str(self._expected)

        @param testCase: The L{TestCase} instance which is used to raise a
            test-failing exception when that is necessary.

        @param expected: The exception type expected to be raised.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/_synctest.py