setChatPrivate(steamID) {
		let msg = ByteBuffer.allocate(20, ByteBuffer.LITTLE_ENDIAN);
		msg.writeUint64(toChatID(steamID).getSteamID64()); // steamIdChat
		msg.writeUint64(toChatID(steamID).getSteamID64()); // steamIdUserToActOn
		msg.writeUint32(EChatAction.LockChat);
		this._send(EMsg.ClientChatAction, msg.flip());
	}
Sets a chat room private (invitation required to join, unless a member of the group [if the chat is a Steam group chat])
@param {(SteamID|string)} steamID - The SteamID of the chat room to make private (as a SteamID object or a string which can parse into one)
@deprecated This uses the old-style chat rooms, if you want new chat instead use this.chat