def SetDataMenuBar(G2frame, menu=None):
    """Set the menu for the data frame.

    Note that data frame items do not have menus, for these (menu=None)
    display the standard main menu for the data tree window.
    """
    if menu is None:
        G2frame.SetMenuBar(G2frame.GSASIIMenu)
    else:
        G2frame.SetMenuBar(menu)
