docs: private String toAbsolute(String location) {
  
          if (location == null) {
              return location;
          }
  
          boolean leadingSlash = location.startsWith("/");
  
          if (leadingSlash || !hasScheme(location)) {
              return RedirectBuilder.redirect(exchange, location, false);
          } else {
              return location;
          }
  
      }