code: public function format($diff, $lineTemplate = '%s')
      {
          $isDecorated = $this->isDecoratedOutput;
  
          $template = $isDecorated
              ? $this->template
              : Preg::replace('/<[^<>]+>/', '', $this->template)
          ;
  
          return sprintf(
              $template,
              implode(
                  PHP_EOL,
                  array_map(
                      static function ($line) use ($isDecorated, $lineTemplate) {
                          if ($isDecorated) {
                              $count = 0;
                              $line = Preg::replaceCallback(
                                  [
                                      '/^(\+.*)/',
                                      '/^(\-.*)/',
                                      '/^(@.*)/',
                                  ],
                                  function ($matches) {
                                      if ('+' === $matches[0][0]) {
                                          $colour = 'green';
                                      } elseif ('-' === $matches[0][0]) {
                                          $colour = 'red';
                                      } else {
                                          $colour = 'cyan';
                                      }
  
                                      return sprintf('<fg=%s>%s</fg=%s>', $colour, OutputFormatter::escape($matches[0]), $colour);
                                  },
                                  $line,
                                  1,
                                  $count
                              );
  
                              if (0 === $count) {
                                  $line = OutputFormatter::escape($line);
                              }
                          }
  
                          return sprintf($lineTemplate, $line);
                      },
                      Preg::split('#\R#u', $diff)
                  )
              )
          );
      }
docs: @param string $diff
  @param string $lineTemplate
  
  @return string