protected void beforeUpdate(ModeledAuthenticatedUser user,
            InternalType object, ModelType model) throws GuacamoleException {

        // By default, do nothing.
        if (!hasObjectPermission(user, model.getIdentifier(), ObjectPermission.Type.UPDATE))
            throw new GuacamoleSecurityException("Permission denied.");

    }
Called before any object is updated through this directory object
service. This function serves as a final point of validation before
the update operation occurs. In its default implementation,
beforeUpdate() performs basic permissions checks.

@param user
    The user updating the existing object.

@param object
    The object being updated.

@param model
    The model of the object being updated.

@throws GuacamoleException
    If the object is invalid, or an error prevents validating the given
    object.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/base/ModeledDirectoryObjectService.java