How can I modify the googlemap url in the google charts into http rather than the original https?

[HT Liu]

Hi, 

As known, the googlemap api used in google charts: https://maps.googleapis.com

And how can I modify the url into other mapurl , such as http://maps.google.cn/maps/api/js

Is there an api for it? such as :

google.charts.load("current", {
        "packages":["map"],
        // Note: you will need to get a mapsApiKey for your project.
        // See: https://developers.google.com/chart/interactive/docs/basic_load_libs#load-settings
        "mapsApiKey": "AIzaSyD-9tSrke72PouQMnMX-a7eZSW0jkFMBWY"
    });