code: func (c *Client) CollaboratorList(appIdentity string, lr *ListRange) ([]Collaborator, error) {
  	req, err := c.NewRequest("GET", "/apps/"+appIdentity+"/collaborators", nil, nil)
  	if err != nil {
  		return nil, err
  	}
  
  	if lr != nil {
  		lr.SetHeader(req)
  	}
  
  	var collaboratorsRes []Collaborator
  	return collaboratorsRes, c.DoReq(req, &collaboratorsRes)
  }
docs: // List existing collaborators.
  //
  // appIdentity is the unique identifier of the Collaborator's App. lr is an
  // optional ListRange that sets the Range options for the paginated list of
  // results.