send(data) {
		if (this.sessionKey) {
			data = SteamCrypto.symmetricEncryptWithHmacIv(data, this.sessionKey);
		}

		if (!this.stream) {
			this._debug('Tried to send message, but there is no stream');
			return;
		}

		let buf = Buffer.alloc(4 + 4 + data.length);
		buf.writeUInt32LE(data.length, 0);
		buf.write(MAGIC, 4);
		data.copy(buf, 8);

		try {
			this.stream.write(buf);
		} catch (error) {
			this._debug('Error writing to socket: ' + error.message);
			this._fatal(error);
		}
	}
Send data over the connection
@param {Buffer} data