Callback not working for tests

The test is not able to handle callbacks properly. Callback in never executed.

exports['AddvertexTest'] = function () {
    addVertex();
}

function addVertex() {
    console.log('Running Add Vertex1');
    client.execute("g.addV('person').property('id', 'thomas').property('firstName', 'Thomas').property('age', 44).property('userid', 1)", {}, (err, results) => {
        **if (err) {
            assert.ok(false, "Vertex adition failed");
        }

        console.log("Result: %s\n", JSON.stringify(results));
        assert.ok(true, "Vertex adition Successful!!");**
    });
}

dropVertex() and addVertex() execute request asynchronously with callbacks. The tests does not execute the callback.

Expected Behavior

Execute callback

Actual Behavior

Callback not executed.

• NTVS Version: 1.3
• Visual Studio Version: 2015
• Node.js Version:

Steps to Reproduce

1. Add test with callbacks
2. run the test.

The report's entry point is the supplied AddvertexTest/addVertex reproduction; first run it in the stated NTVS 1.3 and Visual Studio 2015 context and inspect whether the asynchronous request reaches its callback. Done means the callback executes and the success or failure assertions behave as described.