Cache queries

        :param timeout: cache timeout
        :param cache_none: cache None result

        Usage::

        >>> Model.cached(60).query({...})

def cached(cls, timeout=60, cache_none=False):
        """ Cache queries

        :param timeout: cache timeout
        :param cache_none: cache None result

        Usage::

        >>> Model.cached(60).query({...})
        """
        return CachedModel(cls=cls, timeout=timeout, cache_none=cache_none)