code: func (s *ChecksService) UpdateCheckRun(ctx context.Context, owner, repo string, checkRunID int64, opt UpdateCheckRunOptions) (*CheckRun, *Response, error) {
  	u := fmt.Sprintf("repos/%v/%v/check-runs/%v", owner, repo, checkRunID)
  	req, err := s.client.NewRequest("PATCH", u, opt)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	req.Header.Set("Accept", mediaTypeCheckRunsPreview)
  
  	checkRun := new(CheckRun)
  	resp, err := s.client.Do(ctx, req, checkRun)
  	if err != nil {
  		return nil, resp, err
  	}
  
  	return checkRun, resp, nil
  }
docs: // UpdateCheckRun updates a check run for a specific commit in a repository.
  //
  // GitHub API docs: https://developer.github.com/v3/checks/runs/#update-a-check-run