def register_add_user_command(self, add_user_func):
        """
        Add the add-user command to the parser and call add_user_func(project_name, user_full_name, auth_role)
        when chosen.
        :param add_user_func: func Called when this option is chosen: upload_func(project_name, user_full_name, auth_role).
        """
        description = "Gives user permission to access a remote project."
        add_user_parser = self.subparsers.add_parser('add-user', description=description)
        add_project_name_or_id_arg(add_user_parser, help_text_suffix="add a user to")
        user_or_email = add_user_parser.add_mutually_exclusive_group(required=True)
        add_user_arg(user_or_email)
        add_email_arg(user_or_email)
        _add_auth_role_arg(add_user_parser, default_permissions='project_admin')
        add_user_parser.set_defaults(func=add_user_func)