protected Collection<AuthenticationMetaDataPopulator> getAuthenticationMetadataPopulatorsForTransaction(
        final AuthenticationTransaction transaction) {
        return authenticationEventExecutionPlan.getAuthenticationMetadataPopulators(transaction);
    }
This is {@link DefaultAuthenticationManager}, which provides common operations
around an authentication manager implementation.

@author Misagh Moayyed
@since 5.0.0
core/cas-server-core-authentication-api/src/main/java/org/apereo/cas/authentication/DefaultAuthenticationManager.java