Capture chrome screen image and send it back. If the screen is currently 
    at qr scanning phase, return the image of qr only, else return image of full
    screen

def get_screen():
    """Capture chrome screen image and send it back. If the screen is currently 
    at qr scanning phase, return the image of qr only, else return image of full
    screen"""
    img_title = 'screen_' + g.client_id + '.png'
    image_path = STATIC_FILES_PATH + img_title
    if g.driver_status != WhatsAPIDriverStatus.LoggedIn:
        try:
            g.driver.get_qr(image_path)
            return send_file(image_path, mimetype='image/png')
        except Exception as err:
            pass
    g.driver.screenshot(image_path)
    return send_file(image_path, mimetype='image/png')