from twisted.internet.defer import Deferred

def myErrback(failure):
    print(failure)

d = Deferred()
d.addErrback(myErrback)
d.errback(ValueError("Triggering errback."))
print("errback show over")


from twisted.internet.defer import Deferred

def myErrback(failure):
    print(failure)

d = Deferred()
d.addErrback(myErrback)
d.errback(ValueError("Triggering errback."))
print("errback show over")

