docs: private static IconSet resolveIconSet(String iconCode) {
          CharSequence unicode;
  
          for (IconSet set : getRegisteredIconSets()) {
  
              if (set.fontPath().equals(FontAwesome.FONT_PATH) || set.fontPath().equals(Typicon.FONT_PATH) || set.fontPath().equals(MaterialIcons.FONT_PATH)) {
                  continue; // already checked previously, ignore
              }
  
              unicode = set.unicodeForKey(iconCode);
  
              if (unicode != null) {
                  return set;
              }
          }
  
          String message = String.format("Could not find FontIcon value for '%s', " +
                  "please ensure that it is mapped to a valid font", iconCode);
  
          throw new IllegalArgumentException(message);
      }