Part of elisa.core.utils.cancellable_defer View In Hierarchy
see twisted.internet.defer.Deferred
.
Cancel this deferred.
If the deferred is waiting on another deferred, forward the cancellation to the other deferred.
If the deferred has not yet been errback'd/callback'd, call the canceller function provided to the constructor. If that function does not do a callback/errback, or if no canceller function was provided, errback with CancelledError.
Otherwise, raise AlreadyCalledError.