original_string: public function persist($identifier, ParameterBagInterface $parameterBag)
      {
          $stateFilename = $this->getStateFilename($identifier);
          if (!touch($stateFilename) || (file_exists($stateFilename) && !is_writable($stateFilename))) {
              throw new IOException("State isn't writable!");
          }
  
          file_put_contents($stateFilename, serialize($parameterBag));
      }
code: public function persist($identifier, ParameterBagInterface $parameterBag)
      {
          $stateFilename = $this->getStateFilename($identifier);
          if (!touch($stateFilename) || (file_exists($stateFilename) && !is_writable($stateFilename))) {
              throw new IOException("State isn't writable!");
          }
  
          file_put_contents($stateFilename, serialize($parameterBag));
      }
code_tokens: public function persist ( $ identifier , ParameterBagInterface $ parameterBag ) { $ stateFilename = $ this -> getStateFilename ( $ identifier ) ; if ( ! touch ( $ stateFilename ) || ( file_exists ( $ stateFilename ) && ! is_writable ( $ stateFilename ) ) ) { throw new IOException ( "State isn't writable!" ) ; } file_put_contents ( $ stateFilename , serialize ( $ parameterBag ) ) ; }
docstring: Puts the parameter bag to a persistent storage.
  
  @param string                $identifier
  @param ParameterBagInterface $parameterBag
  
  @throws IOException If the state file isn't writable.
  
  @return void
docstring_tokens: Puts the parameter bag to a persistent storage .