original_string: final public function handle(RequestInterface $request)
      {
          $processed = $this->processing($request);
  
          if ($processed === null) {
              // the request has not been processed by this handler => see the next
              if ($this->successor !== null) {
                  $processed = $this->successor->handle($request);
              }
          }
  
          return $processed;
      }
code: final public function handle(RequestInterface $request)
      {
          $processed = $this->processing($request);
  
          if ($processed === null) {
              // the request has not been processed by this handler => see the next
              if ($this->successor !== null) {
                  $processed = $this->successor->handle($request);
              }
          }
  
          return $processed;
      }
code_tokens: final public function handle ( RequestInterface $ request ) { $ processed = $ this -> processing ( $ request ) ; if ( $ processed === null ) { // the request has not been processed by this handler => see the next if ( $ this -> successor !== null ) { $ processed = $ this -> successor -> handle ( $ request ) ; } } return $ processed ; }
docstring: This approach by using a template method pattern ensures you that
  each subclass will not forget to call the successor
  
  @param RequestInterface $request
  
  @return string|null
docstring_tokens: This approach by using a template method pattern ensures you that each subclass will not forget to call the successor