code: func (s *RepositoriesService) ListContributors(ctx context.Context, owner string, repository string, opt *ListContributorsOptions) ([]*Contributor, *Response, error) {
  	u := fmt.Sprintf("repos/%v/%v/contributors", owner, repository)
  	u, err := addOptions(u, opt)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	req, err := s.client.NewRequest("GET", u, nil)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	var contributor []*Contributor
  	resp, err := s.client.Do(ctx, req, &contributor)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	return contributor, resp, nil
  }
docs: // ListContributors lists contributors for a repository.
  //
  // GitHub API docs: https://developer.github.com/v3/repos/#list-contributors