src/vs/editor/browser/services/abstractCodeEditorService.ts/DecorationSubTypeOptionsProvider/constructor
class DecorationSubTypeOptionsProvider:	constructor(themeService: IThemeService, styleSheet: GlobalStyleSheet | RefCountedStyleSheet, providerArgs: ProviderArguments) {
		this._styleSheet = styleSheet;
		this._styleSheet.ref();
		this._parentTypeKey = providerArgs.parentTypeKey!;
		this.refCount = 0;

		this._beforeContentRules = new DecorationCSSRules(ModelDecorationCSSRuleType.BeforeContentClassName, providerArgs, themeService);
		this._afterContentRules = new DecorationCSSRules(ModelDecorationCSSRuleType.AfterContentClassName, providerArgs, themeService);
	}