'Implement the ``IS NOT`` operator.
Normally, ``IS NOT`` is generated automatically when comparing to a
value of ``None``, which resolves to ``NULL``.  However, explicit
usage of ``IS NOT`` may be desirable if comparing to boolean values
on certain platforms.
.. versionadded:: 0.7.9
.. seealso:: :meth:`.ColumnOperators.is_`'

def isnot(self, other):

    return self.operate(isnot, other)
