def _check_denied_group(self):
denied_group_dn = self.settings.DENY_GROUP<EOL>if denied_group_dn is not None:<EOL><INDENT>is_member = self._get_groups().is_member_of(denied_group_dn)<EOL>if is_member:<EOL><INDENT>raise self.AuthenticationFailed("<STR_LIT>")<EOL><DEDENT><DEDENT>return True<EOL>
Returns True if the negative group requirement (AUTH_LDAP_DENY_GROUP)
is met. Always returns True if AUTH_LDAP_DENY_GROUP is None.