ExtensionUtils defines utility methods for implementing extensions.
Appends a <style> tag to the document's head.
Appends a <link> tag to the document's head.
Returns a path to an extension module.
Returns a URL to an extension module.
Performs a GET request using a path relative to an extension module.
The resulting URL can be retrieved in the resolve callback by accessing
Loads a style sheet (CSS or LESS) relative to the extension module.
Parses LESS code and returns a promise that resolves with plain CSS code.
Pass the {@link url} argument to resolve relative URLs contained in the code. Make sure URLs in the code are wrapped in quotes, like so: background-image: url("image.png");