private function handleMustacheErrors($errno, $errstr, $errfile, $errline)
    {
        if (!empty($this->lastTemplate)) {
            if (function_exists('newrelic_add_custom_parameter')) {
                call_user_func(
                    'newrelic_add_custom_parameter',
                    'contactclientToken',
                    $this->lastTemplate
                );
            }
        }
        if (!empty($this->context)) {
            if (function_exists('newrelic_add_custom_parameter')) {
                call_user_func(
                    'newrelic_add_custom_parameter',
                    'contactclientContext',
                    json_encode($this->context)
                );
            }
        }
        $this->logger->error(
            'Contact Client '.$this->contactClient->getId().
            ': Warning issued with Template: '.$this->lastTemplate.' Context: '.json_encode($this->context)
        );

        return true;
    }