@staticmethod
def write_partition(df, path, fs, filename, partition_on, return_metadata,
    **kwargs):
    """
        Output a partition of a dask.DataFrame. This will correspond to
        one output file, unless partition_on is set, in which case, it will
        correspond to up to one file in each sub-directory.

        Parameters
        ----------
        df: dask.dataframe.DataFrame
        path: str
            Destination directory for data.  Prepend with protocol like ``s3://``
            or ``hdfs://`` for remote data.
        fs: FileSystem
        filename: str
        partition_on: List(str)
            Column(s) to use for dataset partitioning in parquet.
        return_metadata : bool
            Whether to return list of instances from this write, one for each
            output file. These will be passed to write_metadata if an output
            metadata file is requested.
        **kwargs: dict
            Other keyword arguments (including `fmd` and `index_cols`)

        Returns
        -------
        List of metadata-containing instances (if `return_metadata` is `True`)
        or empty list
        """
    raise NotImplementedError
