def METHOD_NAME(self, role, group, site, authzfunc):
    """Format the authorization rules into lists and verify if the given
    user is allowed to access."""
    if authzfunc is None:
        authzfunc = self.defaultAuth
    # TOFIX: put role, group and site into canonical form
    # Turns arguments into lists
    if role and isinstance(role, str):
        role = [role]
    if group and isinstance(group, str):
        group = [group]
    if site and isinstance(site, str):
        site = [site]
    # Finally checks if the user is allowed
    if not authzfunc(get_user_info(), role, group, site):
        # Authorization denied
        raise cherrypy.HTTPError(403, "You are not allowed to access this resource, authz denied")