setGroupUserRoleState(groupId, userSteamId, roleId, roleState, callback) {
		return StdLib.Promises.timeoutCallbackPromise(10000, null, callback, true, (resolve, reject) => {
			this.user._sendUnified(roleState ? 'ChatRoom.AddRoleToUser#1' : 'ChatRoom.DeleteRoleFromUser#1', {
				chat_group_id: groupId,
				role_id: roleId,
				steamid: Helpers.steamID(userSteamId).toString()
			}, (body, hdr) => {
				let err = Helpers.eresultError(hdr.proto);
				if (err) {
					return reject(err);
				}

				resolve();
			});
		});
	}
Add or remove a role to a group user, provided you have the appropriate permissions.
@param {int} groupId
@param {SteamID|string} userSteamId
@param {int} roleId
@param {boolean} roleState
@param {function} [callback]
@returns {Promise}