def asfreq(self) -> DataArray:
        """Return values of original object at the new up-sampling frequency;
        essentially a re-index with new times set to NaN.

        Returns
        -------
        resampled : DataArray
        """
        self._obj = self._drop_coords()
        return self.mean(None if self._dim is None else [self._dim])
Return values of original object at the new up-sampling frequency;
        essentially a re-index with new times set to NaN.

        Returns
        -------
        resampled : DataArray
        
xarray/core/resample.py