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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_version(self, filename=None, version=-1, session=None, **kwargs):
 """Get a file from GridFS by ``"filename"`` or metadata fields. Returns a version of the file in GridFS whose filename matches `filename` and whose metadata fields match the supplied keyword arguments, as an instance of :class:`~gridfs.grid_file.GridOut`. Version numbering is a convenience atop the GridFS API provided by MongoDB. If more than one file matches the query (either by `filename` alone, by metadata fields, or by a combination of both), then version ``-1`` will be the most recently uploaded matching file, ``-2`` the second most recently uploaded, etc. Version ``0`` will be the first version uploaded, ``1`` the second version, etc. So if three versions have been uploaded, then version ``0`` is the same as version ``-3``, version ``1`` is the same as version ``-2``, and version ``2`` is the same as version ``-1``. Raises :class:`~gridfs.errors.NoFile` if no such version of that file exists. :Parameters: - `filename`: ``"filename"`` of the file to get, or `None` - `version` (optional):
 version of the file to get (defaults to -1, the most recent version uploaded) - `session` (optional):
 a :class:`~pymongo.client_session.ClientSession` - `**kwargs` (optional):
 find files by custom metadata. .. versionchanged:: 3.6 Added ``session`` parameter. .. versionchanged:: 3.1 ``get_version`` no longer ensures indexes. """

        query = kwargs
        if filename is not None:
            query["filename"] = filename

        cursor = self.__files.find(query, session=session)
        if version < 0:
            skip = abs(version) - 1
            cursor.limit(-1).skip(skip).sort("uploadDate", DESCENDING)
        else:
            cursor.limit(-1).skip(version).sort("uploadDate", ASCENDING)
        try:
            doc = next(cursor)
            return GridOut(
                self.__collection, file_document=doc, session=session)
        except StopIteration:
            raise NoFile("no version %d for filename %r" % (version, filename))