src/vs/workbench/api/common/extHostTypeConverters.ts/isDecorationOptionsArr
export function isDecorationOptionsArr(something: vscode.Range[] | vscode.DecorationOptions[]): something is vscode.DecorationOptions[] {
	if (something.length === 0) {
		return true;
	}
	return isDecorationOptions(something[0]) ? true : false;
}