import 'dart:math'; import 'package:flutter/material.dart'; extension IterableHelper on Iterable { T? firstWhereOrNull(bool Function(T) test) => where(test).firstOrNull; } extension NullableIterableHelper on Iterable { Iterable whereNotNull() => where((element) => element != null).cast(); } extension ListHelper on List { // List shuffle([int? seed]) { // Random r = Random(seed); // var items = [...this]; // for (var i = length - 1; i > 0; i--) { // var n = r.nextInt(i + 1); // // var temp = items[i]; // items[i] = items[n]; // items[n] = temp; // } // // return items; // } }