docs: public String getAbsoluteUri(String relativeUri, String baseUri) {
  
          if ((relativeUri == null) || (relativeUri.charAt(0) == '/') || (relativeUri.startsWith("#"))) {
  
              return relativeUri;
          }
  
          // if we are on a windows system, we must add a ":" in the uri later
          String windowsAddition = "";
          if (File.separator.equals("\\")) {
              windowsAddition = ":";
          }
  
          try {
              URL baseUrl = new URL("file://");
              URL url = new URL(new URL(baseUrl, "file://" + baseUri), relativeUri);
              if (url.getQuery() == null) {
                  if (url.getRef() == null) {
                      return url.getHost() + windowsAddition + url.getPath();
                  } else {
                      return url.getHost() + windowsAddition + url.getPath() + "#" + url.getRef();
                  }
              } else {
                  return url.getHost() + windowsAddition + url.getPath() + "?" + url.getQuery();
              }
          } catch (MalformedURLException e) {
              return relativeUri;
          }
      }