from time import sleep
from typing import Callable
from typing import Optional

def wait_until_true(readiness_checker: Callable[[],bool],*,interval: float =0.1, timeout_sec: Optional[float] = None):
    elapsed = 0.0
    if timeout_sec is None:
        timeout_sec = 10e16
    while not readiness_checker or elapsed > timeout_sec:
        sleep(interval)
        elapsed += interval
    if elapsed > timeout_sec:
        raise TimeoutError()