There does appear to be an unofficial way to do this, though - naturally - it may not last: https://github.com/mohamedmansour/google-plus-extension-jsapi https:

There does appear to be an unofficial way to do this, though - naturally - it may not last: https://github.com/mohamedmansour/google-plus-extension-jsapi https://github.com/mohamedmansour/google-plus-extension-jsap...