@Override
    public String toString() {
        return new StringJoiner(", ", EmailTemplateFileEntry.class.getSimpleName() + "[", "]")
                .add("subject='" + subject + "'")
                .add("html=" + html)
                .add("plain=" + plain)
                .add("category=" + category)
                .toString();
    }
Email template entry in the format stored in the template file index (notification-template-index).

@author Marc Savy {@literal <marc@blackparrotlabs.io>}
manager/api/rest-impl/src/main/java/io/apiman/manager/api/notifications/email/EmailTemplateFileEntry.java