@Override
    public void removeObjects(Set<String> identifiers) throws GuacamoleException {

        // Nothing to do if nothing provided
        if (identifiers.isEmpty())
            return;

        // Delete relations only if permission is granted
        if (canAlterRelation(identifiers))
            getObjectRelationMapper().delete(parent.getModel(), identifiers,
                    getCaseSensitivity());

        // User lacks permission to remove user groups
        else
            throw new GuacamoleSecurityException("Permission denied.");

    }
Returns whether the current user has permission to alter the status of
the relation between the parent object and the given child objects.

@param identifiers
    The identifiers of all objects on the child side of the one-to-many
    relation being changed.

@return
    true if the user has permission to make the described changes,
    false otherwise.

@throws GuacamoleException
    If permission to query permission status is denied.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/base/RelatedObjectSet.java