@Override
        public void render(final TickBoxCell cell,
                           final Context context,
                           final TickBoxState value,
                           final SafeHtmlBuilder sb) {
            // Get the view data.
            final Object key = context.getKey();
            final TickBoxState viewData = cell.getViewData(key);
            if (viewData != null && viewData.equals(value)) {
                cell.clearViewData(key);
            }

            if (value != null) {
                sb.append(getHTML(value));
            }
        }
Render the button and its contents.

@param cell    the cell that is being rendered
@param context the {@link Context} of the cell
@param value   the value that generated the content
@param sb      the {@link SafeHtmlBuilder} to render into
stroom-core-client-widget/src/main/java/stroom/cell/tickbox/client/TickBoxCell.java