@Override
    protected List<UserProvider> getUserProviders()
    {
        return userProviders;
    }
Delegate UserProvider operations among up to three configurable provider implementation classes.

This class related to, but is distinct from {@link MappedUserProvider}. The Hybrid variant of the provider iterates
over providers, operating on the first applicable instance. The Mapped variant, however, maps each user to exactly
one provider.

@author Marc Seeger
@author Chris Neasbitt
@author Tom Evans
@author Guus der Kinderen
xmppserver/src/main/java/org/jivesoftware/openfire/user/HybridUserProvider.java