@Override
            public void update(ConnectionGroup connectionGroup) throws GuacamoleException {

                // Unwrap the existing ConnectionGroup
                if (connectionGroup instanceof KsmConnectionGroup)
                    connectionGroup = ((KsmConnectionGroup) connectionGroup).getUnderlyingConnectionGroup();

                // Process attribute values before saving
                connectionGroup.setAttributes(
                    attributeService.processAttributes(
                        connectionGroup.getAttributes()));

                super.update(connectionGroup);

            }
Service for retrieving any custom attributes defined for the
current vault implementation and processing of said attributes.
extensions/guacamole-vault/modules/guacamole-vault-ksm/src/main/java/org/apache/guacamole/vault/ksm/user/KsmDirectoryService.java