@extensionmethod(BlockingObservable, alias="to_string")  # noqa
def to_marbles(self, scheduler=None):

    latch = threading.Event()
    ret = [None]

    def on_next(value):
        ret[0] = value

    self.observable.to_marbles(scheduler=scheduler).subscribe(on_next, on_completed=latch.set)

    # Block until the subscription completes and then return
    latch.wait()

    return ret[0]
Validates the captcha provided.
dataset/ETHPy150Open ReactiveX/RxPY/rx/testing/marbles.py/to_marbles--crossover with--dataset/ETHPy150Open matrix-org/synapse/synapse/handlers/register.py/RegistrationHandler._validate_captcha