code: func (s *TeamsService) IsTeamRepo(ctx context.Context, team int64, owner string, repo string) (*Repository, *Response, error) {
  	u := fmt.Sprintf("teams/%v/repos/%v/%v", team, owner, repo)
  	req, err := s.client.NewRequest("GET", u, nil)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	headers := []string{mediaTypeOrgPermissionRepo, mediaTypeNestedTeamsPreview}
  	req.Header.Set("Accept", strings.Join(headers, ", "))
  
  	repository := new(Repository)
  	resp, err := s.client.Do(ctx, req, repository)
  	if err != nil {
  		return nil, resp, err
  	}
  
  	return repository, resp, nil
  }
docs: // IsTeamRepo checks if a team manages the specified repository. If the
  // repository is managed by team, a Repository is returned which includes the
  // permissions team has for that repo.
  //
  // GitHub API docs: https://developer.github.com/v3/teams/#check-if-a-team-manages-a-repository