code: def validate(self):
          
          if self.GROUP_ATTRIBUTES and self.GROUPNAME_FIELD not in self.GROUP_ATTRIBUTES.values():
              raise ImproperlyConfigured("LDAP_SYNC_GROUP_ATTRIBUTES must contain '%s'" % self.GROUPNAME_FIELD)
  
          if not self.model._meta.get_field(self.USERNAME_FIELD).unique:
              raise ImproperlyConfigured("LDAP_SYNC_USERNAME_FIELD '%s' must be unique" % self.USERNAME_FIELD)
  
          if self.USER_ATTRIBUTES and self.USERNAME_FIELD not in self.USER_ATTRIBUTES.values():
              raise ImproperlyConfigured("LDAP_SYNC_USER_ATTRIBUTES must contain '%s'" % self.USERNAME_FIELD)
docs: Apply validation rules for loaded settings.