Return a contiguous range that is a superset of this range.

        Returns:
            A VersionRange object representing the span of this range. For
            example, the span of "2+<4|6+<8" would be "2+<8".

def span(self):
        """Return a contiguous range that is a superset of this range.

        Returns:
            A VersionRange object representing the span of this range. For
            example, the span of "2+<4|6+<8" would be "2+<8".
        """
        other = VersionRange(None)
        bound = _Bound(self.bounds[0].lower, self.bounds[-1].upper)
        other.bounds = [bound]
        return other