'Returns a specific tab from this tab group.
If the tab is not allowed or not enabled this method returns ``None``.
If the tab is disabled but you wish to return it anyway, you can pass
``True`` to the allow_disabled argument.'

def get_tab(self, tab_name, allow_disabled=False):

    tab = self._tabs.get(tab_name, None)
    if (tab and tab._allowed and (tab._enabled or allow_disabled)):
        return tab
    return None
