def chunks(self) -> _Chunks | None:
        """
        Tuple of block lengths for this NamedArray's data, in order of dimensions, or None if
        the underlying data is not a dask array.

        See Also
        --------
        NamedArray.chunk
        NamedArray.chunksizes
        xarray.unify_chunks
        """
        data = self._data
        if isinstance(data, _chunkedarray):
            return data.chunks
        else:
            return None

        Tuple of block lengths for this NamedArray's data, in order of dimensions, or None if
        the underlying data is not a dask array.

        See Also
        --------
        NamedArray.chunk
        NamedArray.chunksizes
        xarray.unify_chunks
        
xarray/namedarray/core.py