The result of successfully loading a stylesheet with an Importer.
The contents of the stylesheet.
The URL to use to link to the loaded stylesheet's source code in source
file: URL is ideal because it's accessible to both browsers and
other build tools, but an
http: URL is also acceptable.
If this isn't set, it defaults to a
data: URL that contains the contents
of the loaded stylesheet.
The syntax with which to parse contents.