onPreLogout method
Implementation
void onPreLogout(Future onPreLogout()) {
if (!_preLogout.contains(onPreLogout)) {
_preLogout.add(onPreLogout);
}
}
void onPreLogout(Future onPreLogout()) {
if (!_preLogout.contains(onPreLogout)) {
_preLogout.add(onPreLogout);
}
}