Used when you want to lock state in cache, for a claim. ```python key_name = '...' lock_value = generate_random_value() # UUID or something guaranteed to be unique expiration = ... # Some expiration time, maybe 5 minutes, or whatever makes sense for the operation. cached_lock_value = cache.get_or_create(key_name, lock_value) if cached_lock_value == lock_value: # We acquired the lock. # Do whatever ... # Clear the lock (if it's still owned by us. # Note that it might have fallen out of cache, or we took too long. cached_lock_value = cache.get(key_name) if cached_lock_value == lock_value: cache.delete(key_name) ```