This clause allows requests to be redirected to a Handler based on the
               Handler's Identifier. This allows rapid selection of a Handler from
               amongst many Handlers using a hash-based match, instead of relying on the
               normal linear search that is used to find <Handler> clauses. This
               can be useful in special cases where there are many Handlers, and where a
               PreHandlerHook is able to identify the correct Handler to use.
            When <AuthBy HANDLER> runs, it uses the HandlerId to create the
               name of the desired Handler to use. The named Handler is found based on
               its Identifier, and the request is redirected to that Handler.