Monitor http request in firefox extension?

how I can capture all http request in firefox addon. I am not able to find api example . can anybody tell me how firebug does it for net panel ?

开发者_如何学Python

I want to detect all http request and response in firebug.

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Add an Event Listener to the gBrowser global object, making sure to set usecapture to true. You could also intercept the response.