src/vs/editor/browser/services/abstractCodeEditorService.ts/AbstractCodeEditorService/resolveDecorationCSSRules
class AbstractCodeEditorService:	public resolveDecorationCSSRules(decorationTypeKey: string) {
		const provider = this._decorationOptionProviders.get(decorationTypeKey);
		if (!provider) {
			return null;
		}
		return provider.resolveDecorationCSSRules();
	}