original_string: public function setRootDir(/*# string */ $rootDir)
      {
          $dir = realpath($rootDir);
  
          if (false === $dir) {
              throw new InvalidArgumentException(
                  Message::get(Message::CONFIG_ROOT_INVALID, $rootDir),
                  Message::CONFIG_ROOT_INVALID
              );
          }
  
          $this->root_dir = $dir . \DIRECTORY_SEPARATOR;
  
          return $this;
      }
code: public function setRootDir(/*# string */ $rootDir)
      {
          $dir = realpath($rootDir);
  
          if (false === $dir) {
              throw new InvalidArgumentException(
                  Message::get(Message::CONFIG_ROOT_INVALID, $rootDir),
                  Message::CONFIG_ROOT_INVALID
              );
          }
  
          $this->root_dir = $dir . \DIRECTORY_SEPARATOR;
  
          return $this;
      }
code_tokens: public function setRootDir ( /*# string */ $ rootDir ) { $ dir = realpath ( $ rootDir ) ; if ( false === $ dir ) { throw new InvalidArgumentException ( Message :: get ( Message :: CONFIG_ROOT_INVALID , $ rootDir ) , Message :: CONFIG_ROOT_INVALID ) ; } $ this -> root_dir = $ dir . \ DIRECTORY_SEPARATOR ; return $ this ; }
docstring: Set config file root directory
  
  @param  string $rootDir
  @return $this
  @throws InvalidArgumentException if root dir is unknown
  @access public
  @api
docstring_tokens: Set config file root directory