EDD\HelpScout\Endpoint::get_customer_emails_by_license_key PHP Method

    private function get_customer_emails_by_license_key()
    {
        if (!class_exists('EDD_Software_Licensing')) {
            return array();
        }
        $subject_line = $this->data['ticket']['subject'];
        $last_word = substr($subject_line, strrpos($subject_line, ' ') + 1);
        // only search for license key if last word actually looks like a license key
        // this check is dirty, as people could be using the filter in EDD for generating their own type of licenes key...
        if (strlen($last_word) === 32) {
            $license_key = $last_word;
            $edd_sl = edd_software_licensing();
            $license_id = $edd_sl->get_license_by_key($license_key);
            $payment_id = get_post_meta($license_id, '_edd_sl_payment_id', true);
            $user_info = edd_get_payment_meta_user_info($payment_id);
            if (!empty($user_info['email'])) {
                return array($user_info['email']);
            }
        }
        return array();
    }