original_string: public function prepare_package_file() {
          if (empty($this->singlefile) && empty($this->multifiles)) {
              throw new portfolio_caller_exception('invalidpreparepackagefile', 'portfolio', $this->get_return_url());
          }
          if ($this->singlefile) {
              return $this->exporter->copy_existing_file($this->singlefile);
          }
          foreach ($this->multifiles as $file) {
              $this->exporter->copy_existing_file($file);
          }
      }
code: public function prepare_package_file() {
          if (empty($this->singlefile) && empty($this->multifiles)) {
              throw new portfolio_caller_exception('invalidpreparepackagefile', 'portfolio', $this->get_return_url());
          }
          if ($this->singlefile) {
              return $this->exporter->copy_existing_file($this->singlefile);
          }
          foreach ($this->multifiles as $file) {
              $this->exporter->copy_existing_file($file);
          }
      }
code_tokens: public function prepare_package_file ( ) { if ( empty ( $ this -> singlefile ) && empty ( $ this -> multifiles ) ) { throw new portfolio_caller_exception ( 'invalidpreparepackagefile' , 'portfolio' , $ this -> get_return_url ( ) ) ; } if ( $ this -> singlefile ) { return $ this -> exporter -> copy_existing_file ( $ this -> singlefile ) ; } foreach ( $ this -> multifiles as $ file ) { $ this -> exporter -> copy_existing_file ( $ file ) ; } }
docstring: Helper function to copy files into the temp area
  for single or multi file exports.
  
  @return stored_file|bool
docstring_tokens: Helper function to copy files into the temp area for single or multi file exports .