// verify dao auth provider
final DaoAuthenticationProvider p = i.getInstance(DaoAuthenticationProvider.class);
assert p != null : "Unable to obtain a dao auth provider";
// verify AnonymousAuthenticationProvider
final AnonymousAuthenticationProvider ap = i.getInstance(AnonymousAuthenticationProvider.class);
assert ap != null : "Unable to obtain AnonymousAuthenticationProvider";
// verify AuthenticationManager
final AuthenticationManager am = i.getInstance(AuthenticationManager.class);
assert am != null : "Unable to obtain AuthenticationManager";