my.instagram.android: minor cleanup + cachew

my/instagram/android.py

@@ -12,13 +12,16 @@ from typing import Iterator, Sequence, Optional, Dict, Union
 from more_itertools import unique_everseen
 
 from my.core import (
-    get_files, Paths,
+    get_files,
+    Paths,
     make_config,
     make_logger,
     datetime_naive,
     Json,
-    Res, assert_never,
+    Res,
+    assert_never,
 )
+from my.core.cachew import mcachew
 from my.core.sqlite import sqlite_connect_immutable, select
 
 from my.config import instagram as user_config
@@ -26,6 +29,7 @@ from my.config import instagram as user_config
 
 logger = make_logger(__name__)
 
+
 @dataclass
 class instagram_android_config(user_config.android):
     # paths[s]/glob to the exported sqlite databases
@@ -172,6 +176,7 @@ def _entities() -> Iterator[Res[Union[User, _Message]]]:
                     yield e
 
 
+@mcachew(depends_on=inputs)
 def messages() -> Iterator[Res[Message]]:
     id2user: Dict[str, User] = {}
     for x in unique_everseen(_entities()):