refactor: lint fixes

Author: vi3k6i5

tests/unit/test_database.py

@@ -17,7 +17,6 @@
 
 import mock
 from google.api_core import gapic_v1
-from google.cloud.exceptions import NotFound
 from google.cloud.spanner_v1.param_types import INT64
 from google.api_core.retry import Retry
 
@@ -1793,7 +1792,6 @@ class Testing(Exception):
  self.assertIs(pool._session, session)
 
  def test_context_mgr_session_not_found_error(self):
- from google.cloud.spanner_v1.database import SnapshotCheckout
  from google.cloud.exceptions import NotFound
 
  database = _Database(self.DATABASE_NAME)
@@ -1809,14 +1807,12 @@ def test_context_mgr_session_not_found_error(self):
 
  self.assertEqual(pool._session, session)
  with self.assertRaises(NotFound):
- with checkout as snapshot:
- raise NotFound(f"Session not found")
+ with checkout as _:
+ raise NotFound("Session not found")
  # Assert that session-1 was removed from pool and new session was added.
  self.assertEqual(pool._session, new_session)
 
  def test_context_mgr_unknown_error(self):
- from google.cloud.spanner_v1.database import SnapshotCheckout
-
  database = _Database(self.DATABASE_NAME)
  session = _Session(database)
  pool = database._pool = _Pool()
@@ -1829,8 +1825,8 @@ class Testing(Exception):
 
  self.assertEqual(pool._session, session)
  with self.assertRaises(Testing):
- with checkout as snapshot:
- raise Testing(f"Session not found")
+ with checkout as _:
+ raise Testing("Unknown error.")
  # Assert that session-1 was not removed from pool.
  self.assertEqual(pool._session, session)
  pool._new_session.assert_not_called()