How to use the cefpython3.cefpython.MessageLoop function in cefpython3

def init_browser(server_port):
    sys.excepthook = cef.ExceptHook  # To shutdown all CEF processes on error
    cef.Initialize()
    cef.CreateBrowserSync(url="http://localhost:{0}?user=admin&pwd=admin".format(str(server_port)),window_title="OmniDB")
    cef.MessageLoop()
    cef.Shutdown()
    cherrypy.engine.exit()

browserSettings["universal_access_from_file_urls_allowed"] = True
    browserSettings["file_access_from_file_urls_allowed"] = True

    if os.path.exists("icon.ico"):
        icon = os.path.abspath("icon.ico")
    else:
        icon = ""

    windowHandle = cefwindow.CreateWindow(title="pywin32 example",
            className="cefpython3_example", width=1024, height=768,
            icon=icon, windowProc=wndproc)
    windowInfo = cefpython.WindowInfo()
    windowInfo.SetAsChild(windowHandle)
    browser = cefpython.CreateBrowserSync(windowInfo, browserSettings,
            navigateUrl=GetApplicationPath("example.html"))
    cefpython.MessageLoop()
    cefpython.Shutdown()

parent_handle = 0
    # This call has effect only on Mac and Linux.
    # All rect coordinates are applied including X and Y parameters.
    window_info.SetAsChild(parent_handle, [0, 0, 900, 640])
    browser = cef.CreateBrowserSync(url="https://www.google.com/",
                                    window_info=window_info,
                                    window_title="Window size")
    if platform.system() == "Windows":
        window_handle = browser.GetOuterWindowHandle()
        insert_after_handle = 0
        # X and Y parameters are ignored by setting the SWP_NOMOVE flag
        SWP_NOMOVE = 0x0002
        # noinspection PyUnresolvedReferences
        ctypes.windll.user32.SetWindowPos(window_handle, insert_after_handle,
                                          0, 0, 900, 640, SWP_NOMOVE)
    cef.MessageLoop()
    del browser
    cef.Shutdown()

def main():
    cef.Initialize()
    browser = cef.CreateBrowserSync(url="https://www.google.com/",
                                    window_title="OnBeforeClose")
    browser.SetClientHandler(LifespanHandler())
    cef.MessageLoop()
    del browser
    cef.Shutdown()

def main():
    cef.Initialize()
    browser = cef.CreateBrowserSync(
        url="data:text/html,<h1>Mouse clicks snippet</h1>"
            "This text will be selected after one second.<br>"
            "This text will be selected after two seconds.",
        window_title="Mouse clicks")
    browser.SetClientHandler(LifespanHandler())
    cef.MessageLoop()
    del browser
    cef.Shutdown()

def run_cef_gui(url_target, title):
    check_versions()
    sys.excepthook = cef.ExceptHook  # To shutdown all CEF processes on error
    cef.Initialize()
    cef.CreateBrowserSync(url=url_target,
                          window_title=title)
    cef.MessageLoop()
    cef.Shutdown()

def init_browser(server_port):
    sys.excepthook = cef.ExceptHook  # To shutdown all CEF processes on error
    cef.Initialize()
    cef.CreateBrowserSync(url="http://localhost:{0}?user=admin&pwd=admin&token={1}".format(str(server_port),OmniDB.custom_settings.APP_TOKEN),window_title="OmniDB")
    cef.MessageLoop()
    cef.Shutdown()

def main():
    check_versions()
    sys.excepthook = cef.ExceptHook  # To shutdown all CEF processes on error
    cef.Initialize()
    cef.CreateBrowserSync(url="https://www.google.com/",
                          window_title="Hello World!")
    cef.MessageLoop()
    cef.Shutdown()

check_versions()
    sys.excepthook = cef.ExceptHook  # To shutdown all CEF processes on error
    # To change user agent use either "product_version"
    # or "user_agent" options. Explained in Tutorial in
    # "Change user agent string" section.
    settings = {
        # "product_version": "MyProduct/10.00",
        # "user_agent": "MyAgent/20.00 MyProduct/10.00",
    }
    cef.Initialize(settings=settings)
    set_global_handler()
    browser = cef.CreateBrowserSync(url=html_to_data_uri(HTML_code),
                                    window_title="Tutorial")
    set_client_handlers(browser)
    set_javascript_bindings(browser)
    cef.MessageLoop()
    cef.Shutdown()