[Twisted-Python] How to chain deferred calls

[vitaly at synapticvision.com]

hi,
how can I chain in defer methods that could raise exception while  
showing the exception that coming from method? I mean, if I'll do:
return (
   adc1().abc2().abc3().addErrback("Common2AllException")
)
than "Common2AllException" will be raised if abc1() raise Exception,  
but I'd like to see the adc1() own exception (and not  
"Common2AllException") ?



t = Test()
def abc1(self):
   if t.test() is None:
     raise Exception("Error11")
   else:
     return 1

def abc2(self):
   if t.test() is None:
     raise Exception("Error12")
   else:
     return 1

def abc3(self):
   if t.test() is None:
     raise Exception("Error13")
   else:
     return 1




Appreciate the help.