protected function get_print(string $fp = null){
    if ( !$fp ){
      $fp = $this->_get_session('fingerprint');
    }
    if ( $fp ){
      return sha1($this->user_agent.$this->accept_lang./*$this->ip_address .*/ $fp);
    }
    return false;
  }
protected function get_print(string $fp = null){
    if ( !$fp ){
      $fp = $this->_get_session('fingerprint');
    }
    if ( $fp ){
      return sha1($this->user_agent.$this->accept_lang./*$this->ip_address .*/ $fp);
    }
    return false;
  }
protected function get_print ( string $ fp = null ) { if ( ! $ fp ) { $ fp = $ this -> _get_session ( 'fingerprint' ) ; } if ( $ fp ) { return sha1 ( $ this -> user_agent . $ this -> accept_lang . /*$this->ip_address .*/ $ fp ) ; } return false ; }
Returns a "print", ie an identifier based on the user agent
@param false|string $fp
@return string
Returns a print ie an identifier based on the user agent