[Twisted-Python] Cancel/stop Deferred() at any time

[vitaly at synapticvision.com]

Hello,

is there any way to cancel the Deferred callback in those examples?

1.
d = defer.Deferred()
d.addCallback(methodA).addErrback(methodErr)
d.callback(None)

2.
d = methodB().addErrback(methodErr)
wfd = defer.waitForDeferred(d)



Appreciate any help.