def runserver(app=None, reloader=None, debug=None, host=None, port=None):
    """Run the Flask development server i.e. app.run()"""
    debug = debug or app.config.get('DEBUG', False)
    reloader = reloader or app.config.get('RELOADER', False)
    host = host or app.config.get('HOST', '127.0.0.1')
    port = port or app.config.get('PORT', 5000)
    app.run(
        use_reloader=reloader,
        debug=debug,
        host=host,
        port=port
    )
Run the Flask development server i.e. app.run()