code: func (c *Client) CollaboratorCreate(appIdentity string, user string, options *CollaboratorCreateOpts) (*Collaborator, error) {
  	params := struct {
  		User   string `json:"user"`
  		Silent *bool  `json:"silent,omitempty"`
  	}{
  		User: user,
  	}
  	if options != nil {
  		params.Silent = options.Silent
  	}
  	var collaboratorRes Collaborator
  	return &collaboratorRes, c.Post(&collaboratorRes, "/apps/"+appIdentity+"/collaborators", params)
  }
docs: // Create a new collaborator.
  //
  // appIdentity is the unique identifier of the Collaborator's App. user is the
  // unique email address of account or unique identifier of an account. options
  // is the struct of optional parameters for this action.