def __init__(self, coordinator, failTest, newWorker, *args, **kwargs):
        """
        Initialize this L{MemoryPool} with a test case.

        @param coordinator: a worker used to coordinate work in the L{Team}
            underlying this threadpool.
        @type coordinator: L{twisted._threads.IExclusiveWorker}

        @param failTest: A 1-argument callable taking an exception and raising
            a test-failure exception.
        @type failTest: 1-argument callable taking (L{Failure}) and raising
            L{unittest.FailTest}.

        @param newWorker: a 0-argument callable that produces a new
            L{twisted._threads.IWorker} provider on each invocation.
        @type newWorker: 0-argument callable returning
            L{twisted._threads.IWorker}.
        """
        self._coordinator = coordinator
        self._failTest = failTest
        self._newWorker = newWorker
        threadpool.ThreadPool.__init__(self, *args, **kwargs)

        Initialize this L{MemoryPool} with a test case.

        @param coordinator: a worker used to coordinate work in the L{Team}
            underlying this threadpool.
        @type coordinator: L{twisted._threads.IExclusiveWorker}

        @param failTest: A 1-argument callable taking an exception and raising
            a test-failure exception.
        @type failTest: 1-argument callable taking (L{Failure}) and raising
            L{unittest.FailTest}.

        @param newWorker: a 0-argument callable that produces a new
            L{twisted._threads.IWorker} provider on each invocation.
        @type newWorker: 0-argument callable returning
            L{twisted._threads.IWorker}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_threadpool.py