def mod_watch(name, **kwargs):
    '''
    Install/reinstall a package based on a watch requisite

    .. note::
        This state exists to support special handling of the ``watch``
        :ref:`requisite <requisites>`. It should not be called directly.

        Parameters for this function should be set by the state being triggered.
    '''
    sfun = kwargs.pop('sfun', None)
    mapfun = {'purged': purged,
              'latest': latest,
              'removed': removed,
              'installed': installed}
    if sfun in mapfun:
        return mapfun[sfun](name, **kwargs)
    return {'name': name,
            'changes': {},
            'comment': 'pkg.{0} does not work with the watch requisite'.format(sfun),
            'result': False}