src/vs/workbench/common/editor/editorGroupModel.ts/isSerializedEditorGroupModel
export function isSerializedEditorGroupModel(obj?: unknown): obj is ISerializedEditorGroupModel {
	const group = obj as ISerializedEditorGroupModel;

	return !!(obj && typeof obj === 'object' && Array.isArray(group.editors) && Array.isArray(group.mru));
}