   yield intvl
            else:
                return

    def min_start(self):
        &#34;&#34;&#34;
        Returns the smallest known start offset.
        &#34;&#34;&#34;
        return self._by_start[0][0]

    def max_end(self):
        &#34;&#34;&#34;
        Returns the biggest known end offset.
        &#34;&#34;&#34;
        return self._by_end[-1][1]

    def irange(self, minoff=None, maxoff=None, reverse=False, inclusive=(True, True)):
        &#34;&#34;&#34;
        Yields an iterator of in