public boolean isUserGroup() {
        return getModel().getEntityType() == EntityType.USER_GROUP;
    }
Returns whether the underlying entity is a user group. Entities may be
either users or user groups.

@return
    true if the underlying entity is a user group, false otherwise.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/base/ModeledPermissions.java