docs: Location append(String relativeURI) {
          relativeURI = encodeIllegalCharacters(relativeURI);
          if (uri.toString().endsWith("/") && relativeURI.startsWith("/")) {
              relativeURI = relativeURI.substring(1);
          }
          if (!uri.toString().endsWith("/") && !relativeURI.startsWith("/")) {
              relativeURI = "/" + relativeURI;
          }
          return Location.of(URI.create(uri + relativeURI));
      }