code: function(route, args) {
          var index;
  
          // There is a requirement for this route.
          if (typeof(self.routes[route].requirements) != 'undefined') {
              // For each arguments.
              for (index in args) {
                  // If there is a requirement.
                  if (self.routes[route].requirements[index] != null) {
                      // Check if it is fulfilled.
                      var regTest = (new RegExp(self.routes[route].requirements[index]));
                      // If not, replace data with :argument.
                      if (!regTest.test(args[index])) {
                          args[index] = ':' + index
                      }
                  }
              }
          }
          return args
      }
docs: Check if each arguments given has a requirement and check if it is fulfilled.