def _agg(self, how, columns=None, fill_value=np.nan):
        rule = self._rule
        kwargs = self._kwargs
        name = tokenize(self.obj, rule, kwargs, how)

        # Create a grouper to determine closed and label conventions
        newdivs, outdivs = _resample_bin_and_out_divs(self.obj.divisions, rule,
                                                      **kwargs)

        # Repartition divs into bins. These won't match labels after mapping
        partitioned = self.obj.repartition(newdivs, force=True)

        keys = partitioned._keys()
        dsk = partitioned.dask

        args = zip(keys, outdivs, outdivs[1:], ['left']*(1-len(keys)) + [None])
        for i, (k, s, e, c) in enumerate(args):
            dsk[(name, i)] = (_resample_series, k, s, e, c,
                              rule, kwargs, how, fill_value)
        if columns:
            return DataFrame(dsk, name, columns, outdivs)
        return Series(dsk, name, self.obj.name, outdivs)
dataset/ETHPy150Open dask/dask/dask/dataframe/tseries/resample.py/Resampler._agg/swapped operands of `-`