@Override
  public boolean equals(Object target) {
    if (this == target) {
      return true;
    }

    if (target instanceof Position) {
      if (pageNumber == ((Position)target).pageNumber
          && symbolOffsetInPage == ((Position)target).symbolOffsetInPage) {
        return true;
      }
    }
    return false;
  }
@Override
  public boolean equals(Object target)