def __init__(self, stream=sys.stdout, tbformat='default',
                 realtime=False, publisher=None):
        """
        Construct a L{SubunitReporter}.

        @param stream: A file-like object representing the stream to print
            output to. Defaults to stdout.
        @param tbformat: The format for tracebacks. Ignored, since subunit
            always uses Python's standard format.
        @param realtime: Whether or not to print exceptions in the middle
            of the test results. Ignored, since subunit always does this.
        @param publisher: The log publisher which will be preserved for
            reporting events. Ignored, as it's not relevant to subunit.
        """
        if TestProtocolClient is None:
            raise Exception("Subunit not available")
        self._subunit = TestProtocolClient(stream)
        self._successful = True

        Construct a L{SubunitReporter}.

        @param stream: A file-like object representing the stream to print
            output to. Defaults to stdout.
        @param tbformat: The format for tracebacks. Ignored, since subunit
            always uses Python's standard format.
        @param realtime: Whether or not to print exceptions in the middle
            of the test results. Ignored, since subunit always does this.
        @param publisher: The log publisher which will be preserved for
            reporting events. Ignored, as it's not relevant to subunit.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/reporter.py