When you want to update a style that is being used in production, you
may want to test your style updates first.
Duplicate the production map style.
In the duplicated map style, make your changes and publish.
If the duplicated style has just been updated, check the updated
styles to make sure they look as expected. Map features with custom styles
have a solid blue dot next to them. Expand all map features to find all
changes.
Associate the duplicated map style with a different map ID that you can use
to test the style in your staging environment.
Test your style changes in your staging environment.
When you are happy with the results, associate the duplicated map style
with your production map ID.