private void updateFormGroupPanel() {
        formGroupPanel.clear();
        formGroupPanel.add(labelPanel);
        if (descriptionHTML != null) {
            formGroupPanel.add(descriptionPanel);
        }
        if (childWidget != null) {
            formGroupPanel.add(childWidget);
        }
        formGroupPanel.add(feedbackLabel);

    }
Plain text, any HTML will be escaped.
The helpText attr trumps the {@code <form:HelpHTML>} element.
<p>
To programmatically set HTML help text, use {@link FormGroup#overrideHelpText(SafeHtml)}.
</p>
stroom-core-client-widget/src/main/java/stroom/widget/form/client/FormGroup.java