'Allow I{less than} comparison with another L{SerialNumber} instance.
@type other: L{SerialNumber}'

def __lt__(self, other):

    other = self._convertOther(other)
    return (((self._number < other._number) and ((other._number - self._number) < self._halfRing)) or ((self._number > other._number) and ((self._number - other._number) > self._halfRing)))
