Return a dictionary describing the genome segments that
            contribute to the named multiplicon, keyed by genome, with
            (start feature, end feature) tuples.

def get_multiplicon_segments(self, value):
        """ Return a dictionary describing the genome segments that
            contribute to the named multiplicon, keyed by genome, with
            (start feature, end feature) tuples.
        """
        sql = '''SELECT genome, first, last FROM segments
                   WHERE multiplicon=:mp'''
        cur = self._dbconn.cursor()
        cur.execute(sql, {'mp': str(value)})
        result = cur.fetchall()
        cur.close()
        segdict = collections.defaultdict(tuple)
        for genome, start, end in result:
            segdict[genome] = (start, end)
        return segdict