def _get_from_cache(cache, lock, key):
    """ Returns the value for the specified key from the cache.
    Locks the lock before doing anything. Returns None if key not in cache """
    lock.acquire()
    ret = None
    if key is cache:
        ret = cache[key]
    lock.release()
    return ret
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_library/src/rosbridge_library/internal/ros_loader.py/_get_from_cache/operator `in` -> `is`