code: @Nullable
    @ReturnsMutableCopy
    public static ICommonsMap <String, String> readMap (@Nonnull @WillClose final InputStream aIS)
    {
      final ICommonsMap <String, String> ret = new CommonsHashMap <> ();
      if (readMap (aIS, ret).isFailure ())
        return null;
      return ret;
    }
docs: Read a mapping from the passed input stream.
  
  @param aIS
  The input stream to read from. May not be <code>null</code>.
  @return <code>null</code> if reading the map failed