code: private function generateConflictMessage(array $fixerConflicts)
      {
          $message = 'Rule contains conflicting fixers:';
          $report = [];
          foreach ($fixerConflicts as $fixer => $fixers) {
              // filter mutual conflicts
              $report[$fixer] = array_filter(
                  $fixers,
                  static function ($candidate) use ($report, $fixer) {
                      return !\array_key_exists($candidate, $report) || !\in_array($fixer, $report[$candidate], true);
                  }
              );
  
              if (\count($report[$fixer]) > 0) {
                  $message .= sprintf("\n- \"%s\" with \"%s\"", $fixer, implode('", "', $report[$fixer]));
              }
          }
  
          return $message;
      }
docs: @param array<string, string[]> $fixerConflicts
  
  @return string