Reasoning for the `{"key": ""}` parameter:

On the demo page another element is included that only uses an apiKey by setting `gapi.client.setApiKey`

In some cases (not consistently) some Google API methods return a 401 invalid credentials error when both an Authorization header and a `key=xxx` query parameter are provided (there's an issue open for that somewhere for quite a while already...), and I actually ran into this issue while testing.

To prevent this I explicitly set the key query parameter to be empty here, overwriting the default that would come from `gapi.auth.setApiKey`