docs: function statusCode(map) {
                  var code = undefined;
                  if (map) {
                      if (state < 2) {
                          for (code in map) {
                              // Lazy-add the new callback in a way that preserves old ones
                              _statusCode[code] = [_statusCode[code], map[code]];
                          }
                      } else {
                          // Execute the appropriate callbacks
                          jqXHR.always(map[jqXHR.status]);
                      }
                  }
                  return this;
              }