[Twisted-Python] How can I change the default behaviour?

[Leslie Huyan]

Hi:
    I encountered one problem to dig into twisted.
    If I have 2 methods in the call back chain, however I don't want the 
result of the first one to pass to the second one as its arguments, what 
should I do?
    For example:
    defer.addCallbacks(request.write, html)
    defer.addCallbacks(request.setHeader, key, value)

Thank you.