title: How to remove data from a Google Maps Data Layer?
body: <p>I see Google Maps support geojson. Looking at the docs here:
  <a href="https://developers.google.com/maps/documentation/javascript/datalayer#load_geojson">https://developers.google.com/maps/documentation/javascript/datalayer#load_geojson</a></p>
  
  <p>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. </p>