@Override
    public int indexOf(String key) {
        final MenuItemFactory factory = byKey.get(key);
        if (factory == null) return -1;
        else return factories.indexOf(factory);
    }
Default implementation of {@link MenuBarTabHandler}.

@author Emil Forslund
@since  3.1.5
tool-parent/tool-core/src/main/java/com/speedment/tool/core/internal/menubar/MenuBarTabHandlerImpl.java