equal< T> function
Выполняет сравнение двух значений на равенство в JavaScript (==).
Реализация
external bool equal<T>(Object? first, Object? second);
© 2012 the Dart project authors
Licensed under the BSD 3-Clause "New" or "Revised" License.
https://api.dart.dev/stable/2.19.6/dart-js_util/equal.html