Helper function to determine which collapseRequests function to use
        from L{_collapseRequests}, or None for no merging

def getCollapseRequestsFn(self):
        """Helper function to determine which collapseRequests function to use
        from L{_collapseRequests}, or None for no merging"""
        # first, seek through builder, global, and the default
        collapseRequests_fn = self.config.collapseRequests
        if collapseRequests_fn is None:
            collapseRequests_fn = self.master.config.collapseRequests
        if collapseRequests_fn is None:
            collapseRequests_fn = True

        # then translate False and True properly
        if collapseRequests_fn is False:
            collapseRequests_fn = None
        elif collapseRequests_fn is True:
            collapseRequests_fn = self._defaultCollapseRequestFn

        return collapseRequests_fn