private void showActionMenu(final T value, final NativeEvent event) {
        Objects.requireNonNull(menuCreator);
        final List<Item> items = menuCreator.apply(value);
        final PopupPosition popupPosition = new PopupPosition(
                event.getClientX() + 10,
                event.getClientY());
        ShowMenuEvent
                .builder()
                .items(items)
                .popupPosition(popupPosition)
                .fire(hasHandlers);
    }
@param cellTextExtractor Function to supply the text value of the cell
@param menuCreator       A function to create a list of menu items to show when the hover
                         icon is clicked. If the list contains only one item and that item
                         is an instance of {@link stroom.widget.menu.client.presenter.MenuItem}
                         and has a command, then clicking the hover icon will fire the command
                         without showing the menu.
stroom-core-client-widget/src/main/java/stroom/cell/info/client/HoverActionMenuCell.java