original_string: protected function randomLetters()
      {
          for ($i = 0; $i < $this->length; $i++)
          {
              $letters     = $this->letters[mt_rand(0, count($this->letters) - 1)];
              $this->code .= $letters[mt_rand(0, strlen($letters) - 1)];
          }
      }
code: protected function randomLetters()
      {
          for ($i = 0; $i < $this->length; $i++)
          {
              $letters     = $this->letters[mt_rand(0, count($this->letters) - 1)];
              $this->code .= $letters[mt_rand(0, strlen($letters) - 1)];
          }
      }
code_tokens: protected function randomLetters ( ) { for ( $ i = 0 ; $ i < $ this -> length ; $ i ++ ) { $ letters = $ this -> letters [ mt_rand ( 0 , count ( $ this -> letters ) - 1 ) ] ; $ this -> code .= $ letters [ mt_rand ( 0 , strlen ( $ letters ) - 1 ) ] ; } }
docstring: Random generation English & Numbers letters
  
  @return void
docstring_tokens: Random generation English & Numbers letters