pushState method
Implementation
void pushState(dynamic data, String title, String? url) {
url = _resolve(url ?? window.location.href);
final state = _HistoryState(data, title, url);
final stack = _stack;
stack.removeRange(_index + 1, stack.length);
stack.add(state);
_index = stack.length - 1;
_setStateAndDispatchEvent(state);
}