code: function createFallbackHandler( flow ) {
        const { redirectOn, places } = flow;
        return path => {
           log.warn( `Received request for unknown route "${path}".` );
           if( redirectOn.unknownPlace in places ) {
              log.trace( `- Redirecting to error place ("${redirectOn.unknownPlace}").` );
              handleRouteChange( places[ redirectOn.unknownPlace ], {} );
           }
           else if( DEFAULT_PLACE in places ) {
              log.trace( `- Redirecting to default place ("${DEFAULT_PLACE}").` );
              handleRouteChange( places[ DEFAULT_PLACE ], {} );
           }
           else {
              log.trace( '- Got no unknownPlace redirect and no default place. Doing nothing.' );
           }
        };
     }
docs: /////////////////////////////////////////////////////////////////////////////////////////////////////////