unblockUser(steamID, callback) {
		return StdLib.Promises.timeoutCallbackPromise(10000, null, callback, true, (resolve, reject) => {
			if (typeof steamID === 'string') {
				steamID = new SteamID(steamID);
			}

			let buffer = ByteBuffer.allocate(17, ByteBuffer.LITTLE_ENDIAN);
			buffer.writeUint64(this.steamID.getSteamID64());
			buffer.writeUint64(steamID.getSteamID64());
			buffer.writeUint8(0);

			this._send(EMsg.ClientSetIgnoreFriend, buffer.flip(), (body) => {
				body.readUint64(); // unknown
				let err = Helpers.eresultError(body.readUint32());
				return err ? reject(err) : resolve();
			});
		});
	}
Unblock all communication with a user.
@param {(SteamID|string)} steamID - Either a SteamID object of the user to unblock, or a string which can parse into one.
@param {SteamUser~genericEResultCallback} [callback] - Optional. Called with an `err` parameter on completion.
@return {Promise}