hen increasing annotation id for this
            self._key_start = _KeyStartAnnid()
            self._by_start = SortedKeyList(key=self._key_start)
        # for this we sort by end offset only
        self._key_end = _KeyEndAnnid()
        self._by_end = SortedKeyList(key=self._key_end)

    def add(self, start, end, data):
        &#34;&#34;&#34;
        Adds an interval.
        &#34;&#34;&#34;
        self._by_start.add((start, end, data))
        self._by_end.add((start, end, data))

    def update(se