function _makeUid() {
    $date   = date('Ymd\THisT');
    $unique = substr(microtime(), 2, 4);
    $base   = 'aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPrRsStTuUvVxXuUvVwWzZ1234567890';
    $start  = 0;
    $end    = strlen( $base ) - 1;
    $length = 6;
    $str    = null;
    for( $p = 0; $p < $length; $p++ )
      $unique .= $base{mt_rand( $start, $end )};
    $this->uid['value']  = $date.'-'.$unique.'@'.$this->getConfig( 'unique_id' );
    $this->uid['params'] = null;
  }