src/vs/editor/browser/services/abstractCodeEditorService.ts/DecorationSubTypeOptionsProvider/dispose
class DecorationSubTypeOptionsProvider:	public dispose(): void {
		if (this._beforeContentRules) {
			this._beforeContentRules.dispose();
			this._beforeContentRules = null;
		}
		if (this._afterContentRules) {
			this._afterContentRules.dispose();
			this._afterContentRules = null;
		}
		this._styleSheet.unref();
	}