code: public static void setUserDataPath (@Nonnull @Nonempty final String sUserDataPath)
    {
      ValueEnforcer.isTrue (StringHelper.getLength (sUserDataPath) >= 2, "userDataPath is too short");
      ValueEnforcer.isTrue (StringHelper.startsWith (sUserDataPath, '/'), "userDataPath must start with a slash");
  
      s_aRWLock.writeLocked ( () -> s_sUserDataPath = sUserDataPath);
    }
docs: Set the user data path, relative to the URL context and relative to the
  servlet context directory.
  
  @param sUserDataPath
  The path to be set. May neither be <code>null</code> nor empty and
  must start with a "/" character.