def builderAdded(builderName, builder):
    """
        A new Builder has just been added. This method may return an
        IStatusReceiver (probably 'self') which will be subscribed to receive
        builderChangedState and buildStarted/Finished events.

        @type  builderName: string
        @type  builder:     L{buildbot.status.builder.BuilderStatus}
        @rtype: implementer of L{IStatusReceiver}
        """
