@classmethod
def tabManager(cls):
    """
        Class method to get a reference to the tab manager widget.
        
        @return reference to the tab manager widget
        @rtype TabManagerWidget
        """
    if cls._tabManager is None:
        from .TabManager.TabManagerWidget import TabManagerWidget
        cls._tabManager = TabManagerWidget(cls.mainWindow())
        for window in cls.mainWindows():
            cls._tabManager.mainWindowCreated(window, False)
        cls._tabManager.delayedRefreshTree()
    return cls._tabManager
