Fix styling issue around imports for issue 232

stix2/datastore/filesystem.py

@@ -5,14 +5,15 @@ import json
 import os
 import re
 import stat
-import sys
 
 import six
 
 from stix2 import v20, v21
 from stix2.base import _STIXBase
 from stix2.core import parse
-from stix2.datastore import DataSink, DataSource, DataStoreMixin, DataSourceError
+from stix2.datastore import (
+    DataSink, DataSource, DataSourceError, DataStoreMixin,
+)
 from stix2.datastore.filters import Filter, FilterSet, apply_common_filters
 from stix2.utils import format_datetime, get_type_from_id, is_marking