def pick_verse(self, verse_id):
        """Move from picking the verse to teaching the verse.

        The second page that pops up in this application provides a menu
        to choose what verse(s) should be used for a quiz. The selected
        reference is verified; and if the verse could be found, a state
        change occurs. Othewise, the reference is removed from the list."""
        if self.__state == self.OPTIONS.GET_VERSE:
            file = self.__library[self.__quiz_id]
            if verse_id in file:
                bk, ch, v1, v2 = file[verse_id]
                if bk is None:
                    verses = None
                elif v1 is None:
                    verses = self.__bib_svr.fetch_chapter(bk, ch)
                elif v1 == v2:
                    verses = self.__bib_svr.fetch_verse(bk, ch, v1)
                else:
                    verses = self.__bib_svr.fetch_range(bk, ch, v1, v2)
                if verses is None:
                    del file[verse_id]
                else:
                    self.__verses = tuple(verses)
                    for verse in self.__verses:
                        verse.show_hint = False
                    self.__state = self.OPTIONS.TEACH
Move from picking the verse to teaching the verse.

        The second page that pops up in this application provides a menu
        to choose what verse(s) should be used for a quiz. The selected
        reference is verified; and if the verse could be found, a state
        change occurs. Othewise, the reference is removed from the list.
recipes/Python/577046_Bible_Verse_Quiz__statepy/recipe-577046.py