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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_notebook_tab_title(notebook, page_num):
 """Helper function that gets a notebook's tab title given its page number :param notebook: The GTK notebook :param page_num: The page number of the tab, for which the title is required :return: The title of the tab """

    child = notebook.get_nth_page(page_num)
    tab_label_eventbox = notebook.get_tab_label(child)
    return get_widget_title(tab_label_eventbox.get_tooltip_text())