Object for setting and retrieving the default Bing Maps API key.
A Bing API key is only required if you are using
BingMapsImageryProvider
or BingMapsGeocoderService. You can create your own key at
https://www.bingmapsportal.com/.
Members
The default Bing Maps API key to use if one is not provided to the
constructor of an object that uses the Bing Maps API.