code: func (search *Search) Facebook(user string) (*SearchResult, error) {
  	insta := search.inst
  	body, err := insta.sendRequest(
  		&reqOptions{
  			Endpoint: urlSearchFacebook,
  			Query: map[string]string{
  				"query":      user,
  				"rank_token": insta.rankToken,
  			},
  		},
  	)
  	if err != nil {
  		return nil, err
  	}
  	res := &SearchResult{}
  	err = json.Unmarshal(body, res)
  	return res, err
  }
docs: // Facebook search by facebook user.