unused imports

src/black/comments.py

@@ -3,7 +3,7 @@
 from functools import lru_cache
 from typing import Collection, Final, Iterator, List, Optional, Tuple, Union
 
-from black.mode import Mode, Preview
+from black.mode import Mode
 from black.nodes import (
     CLOSING_BRACKETS,
     STANDALONE_COMMENT,

src/black/lines.py

@@ -15,7 +15,7 @@
 )
 
 from black.brackets import COMMA_PRIORITY, DOT_PRIORITY, BracketTracker
-from black.mode import Mode, Preview
+from black.mode import Mode
 from black.nodes import (
     BRACKETS,
     CLOSING_BRACKETS,

src/black/nodes.py

@@ -13,7 +13,7 @@
 from mypy_extensions import mypyc_attr
 
 from black.cache import CACHE_DIR
-from black.mode import Mode, Preview
+from black.mode import Mode
 from black.strings import get_string_prefix, has_triple_quotes
 from blib2to3 import pygram
 from blib2to3.pgen2 import token