experimenting async/await in es6 with node-opcua client

client_es6.js

const opcua = require("node-opcua");

(async () => {

    const client = opcua.OPCUAClient.create();

    client.on("backoff", () => console.log("reconnection in progress", client.endpointUrl));

    const endpointUrl = "opc.tcp://opcuademo.sterfive.com:26543";

    await client.withSessionAsync(endpointUrl, async (session) => {

        const dataValue1 = await session.read({nodeId: "i=2285", attributeId: opcua.AttributeIds.Value});
        console.log(dataValue1.toString());

        const dataValue2 = await session.read({
            nodeId: "ns=1;s=Temperature",
            attributeId: opcua.AttributeIds.Value
        });
        console.log(dataValue2.toString());

    });

    const result = await client.withSessionAsync(endpointUrl, async (session) => {

        return [

            await session.read({
                nodeId: "i=2285",
                attributeId: opcua.AttributeIds.Value
            }),

            await session.read({
                nodeId: "ns=1;s=Temperature",
                attributeId: opcua.AttributeIds.Value
            })
        ];

    });
    console.log(result);

    const result2 = await client.withSessionAsync(endpointUrl, async (session) => {
        return await session.read(
            [
                {
                    nodeId: "i=2285",
                    attributeId: opcua.AttributeIds.Value
                },
                {
                    nodeId: "ns=1;s=Temperature",
                    attributeId: opcua.AttributeIds.Value
                }
            ]
        );
    });
    console.log(result2[0].toString());
    console.log(result2[1].toString());


})();

(async () => {

    const result3 = await client.withSessionAsync(endpointUrl, async (session) => {

        const result = [];

        await session.createSubscription(async (subscription) => {

            const requestedParameters= {
                requestedPublishingInterval: 100,
                requestedLifetimeCount: 60,
                requestedMaxKeepAliveCount: 10,
                maxNotificationsPerPublish: 10,
                publishingEnabled: true,
                priority: 6
            };
            const item ={nodeId:"ns=1;s=Temperature", attributeId: opcua.AttributeIds.Value};
            const monitoredItem = opcua.ClientMonitoredItem.create(subscription, item,requestedParameters);
            monitoredItem.on("changed",(dataValue)=> result.push(result.length));
            await { then: (resolve)=>setTimeout(resolve,1000) };

           //xx await subscription.terminate();

        });

        return result;
    });

    console.log(result3);

})();