I see Google Maps support geojson. Looking at the docs here: https://developers.google.com/maps/documentation/javascript/datalayer#load_geojson
Given the last example with the "Google", how can I make it such that I can click a button to add a new Geojson layer, and another button to toggle/remove the "Google" or even a letter? It seems to me that map.data appears to be a single layer, and is not multiple layers.