code: function watchModules(paths) {
  
      paths || (paths = []);
  
      if (!Array.isArray(paths)) { paths = [paths]; }
  
      // for all directories / files in `config.watch` array
      paths.forEach(function(watchPath) {
  
        // watch modules for changes
        this.watch(watchPath, function(eventPath, stat) {
  
          // delete from the warm cache, the next require will be fresh
          var cached = require.cache[path.resolve(eventPath)];
          var children;
  
          if (!cached) return;
  
          cached.children.forEach(function(module) {
            delete require.cache[module.id]
          });
          delete require.cache[cached.parent.id];
          delete require.cache[path.resolve(eventPath)]
  
        });
  
      }.bind(this));
    }
docs: watches routes, controllers, models for changes and clears require cache
  for those objects to be reloaded or clears routes and reloads them