And I think I do want to return `self._lock_registry[self.context]` deferred from `ComputeAction.execute` after all (fix on its way). This way , if compute is "locked", execute will be "chained" to the previous command's deferred. Note, that if current `self.execute` returns a deferred, if will be chained to `self._lock_registry[self.context]`, thus making it act as the deferred of `self.execute`.