reload method
Refreshes the current user, if signed in.
Implementation
Future<void> reload() async {
_assertSignedOut(_auth);
final user = await _auth._reloadCurrentUser(_idToken);
if (!user.containsKey('displayName')) {
user['displayName'] = null;
}
if (!user.containsKey('photoUrl')) {
user['photoUrl'] = null;
}
_user.addAll(user);
_auth._updateCurrentUserAndEvents(this);
}