original_string: public function exist($keyName) : bool
      {
          # double check
          return
              $this->get($keyName, true) !== true
              && $this->get($keyName, false) !== false;
      }
code: public function exist($keyName) : bool
      {
          # double check
          return
              $this->get($keyName, true) !== true
              && $this->get($keyName, false) !== false;
      }
code_tokens: public function exist ( $ keyName ) : bool { # double check return $ this -> get ( $ keyName , true ) !== true && $ this -> get ( $ keyName , false ) !== false ; }
docstring: Check whether Session is exists or not on segment
  
  @param string $keyName
  @return bool
docstring_tokens: Check whether Session is exists or not on segment