@Override
    public RelatedObjectSet getUserGroups() throws GuacamoleException {
        return RelatedObjectSet.EMPTY_SET;
    }
{@inheritDoc}

<p>This implementation simply an immutable, empty related object set.
Implementations that wish to expose group membership should override
this function.
guacamole-ext/src/main/java/org/apache/guacamole/net/auth/AbstractUser.java