public function clean($value)
  {
    if ($value==='' || $value===null || $value===false)
    {
      return null;
    }

    $tmp = AmbiguityCleaner::get()->clean($value);

    $tmp = str_replace([' ', "\t", "\n"], '', $tmp);
    if ($tmp==='') $tmp = null;

    return $tmp;
  }