Default indexes for a Dataset/DataArray.

    Parameters
    ----------
    coords : Mapping[Any, xarray.Variable]
       Coordinate variables from which to draw default indexes.
    dims : iterable
        Iterable of dimension names.

    Returns
    -------
    Mapping from indexing keys (levels/dimension names) to indexes used for
    indexing along that dimension.

def default_indexes(
    coords: Mapping[Any, Variable],
    dims: Iterable,
) -> 'OrderedDict[Any, pd.Index]':
    """Default indexes for a Dataset/DataArray.

    Parameters
    ----------
    coords : Mapping[Any, xarray.Variable]
       Coordinate variables from which to draw default indexes.
    dims : iterable
        Iterable of dimension names.

    Returns
    -------
    Mapping from indexing keys (levels/dimension names) to indexes used for
    indexing along that dimension.
    """
    return OrderedDict((key, coords[key].to_index())
                       for key in dims if key in coords)