Angular2 how to switch webcams

Question

I am using MediaDevices to use webcam in my angular2 application. I have 2 webcams and I am stuck in switching between 2 webcams. Here is the code I am using right now.

      navigato.mediaDevices.getUserMedia(constraints)
        .then(function (stream) {
            var video: any = document.getElementById('my_camera');
            // Older browsers may not have srcObject
            if (video && "srcObject" in video) {
                video.srcObject = stream;
            } else {
                // Avoid using this in new browsers, as it is going away.
                video.src = window.URL.createObjectURL(stream);
            }
            video.onloadedmetadata = function (e) {
                video.play();
                selff.webCam = true;
            };
        })
        .catch(function (err) {
            console.log(err.name + ": " + err.message);
        });

I have also tried webcamjs library but could not find switching camera functionality in it.