private SafeHtml renderRowValues(List<T> values, int start,
                                         SelectionModel<? super T> selectionModel) {
            try {
                SafeHtmlBuilder sb = new SafeHtmlBuilder();
                hasData.renderRowValues(sb, values, start, selectionModel);
                return sb.toSafeHtml();
            } catch (UnsupportedOperationException e) {
                // If renderRowValues throws, the implementation will render directly in
                // the replaceChildren method.
                return null;
            }
        }
Render a list of row values.

@param values the row values
@param start the absolute start index of the values
@param selectionModel the {@link SelectionModel}
@return null, unless the implementation renders using SafeHtml
stroom-core-client-widget/src/main/java/com/google/gwt/user/cellview/client/AbstractHasData.java