def METHOD_NAME(py_fname, color, prefix='', exe=sys.executable):
    finished = Deferred()
    launched = Deferred()
    protocol = CrossbarProcessProtocol(finished, launched, color, prefix)
    args = [exe, py_fname]
    env = environ.copy()
    env["PYTHONUNBUFFERED"] = "1"
    reactor.spawnProcess(protocol, exe, args, path='.', env=env)
    yield launched
    returnValue(protocol)