_authenticateSetup example

    public function authenticate()
    {
        $this->_authenticateSetup();
        $dbSelect = $this->_authenticateCreateSelect();
        $resultIdentities = $this->_authenticateQuerySelect($dbSelect);

        if (($authResult = $this->_authenticateValidateResultSet($resultIdentities)) instanceof Zend_Auth_Result) {
            return $authResult;
        }

        if ($this->getAmbiguityIdentity() === true) {
            $validIdentities = [];
            $zendAuthCredentialMatchColumn = $this->_zendDb->foldCase('zend_auth_credential_match');
            foreach ($resultIdentities as $identity) {