code: public synchronized void unset(String name) {
      String[] altNames = getAlternateNames(name);
      getOverlay().remove(name);
      getProps().remove(name);
      if (altNames != null && altNames.length > 0) {
        for (String altName : altNames) {
          getOverlay().remove(altName);
          getProps().remove(altName);
        }
      }
    }
docs: Unset a previously set property.