Retrieves an instance of the main Window of the application

Example

async function getWindow() {
    const app = await fin.Application.start({
        uuid: 'app-1',
        name: 'myApp',
        url: 'https://cdn.openfin.co/docs/javascript/stable/tutorial-Application.getWindow.html',
        autoShow: true
    });
    return await app.getWindow();
}

getWindow().then(win => {
    win.showAt(0, 400);
    win.flash();
}).catch(err => console.log(err));