Apply suggestions from code review

Co-authored-by: Yi-Fan Wang <cmp0xff@users.noreply.github.com>

Author: MarcoGorelli

pandas-stubs/core/indexes/base.pyi

@@ -526,7 +526,7 @@ class Index(IndexOpsMixin[S1], ElementOpsMixin[S1]):
     @final
     def asof(self, label: Scalar) -> Scalar: ...
     def asof_locs(
-        self, where: DatetimeIndex, mask: npt.NDArray[np.bool_]
+        self, where: DatetimeIndex, mask: np_ndarray_bool
     ) -> np_1darray_intp: ...
     @overload
     def sort_values(

tests/indexes/test_indexes.py

@@ -1612,9 +1612,9 @@ def test_index_asof_locs() -> None:
 def test_index_sort_values() -> None:
     idx = pd.DatetimeIndex(["2020-01-01", "2020-01-02", "2020-01-03"])
     check(assert_type(idx.sort_values(), pd.DatetimeIndex), pd.DatetimeIndex)
-    sorted_ = idx.sort_values(return_indexer=True)
-    check(assert_type(sorted_[0], pd.DatetimeIndex), pd.DatetimeIndex)
-    check(assert_type(sorted_[1], np_1darray_intp), np_1darray_intp)
+    sorted_index, indexer = idx.sort_values(return_indexer=True)
+    check(assert_type(sorted_index, pd.DatetimeIndex), pd.DatetimeIndex)
+    check(assert_type(indexer, np_1darray_intp), np_1darray_intp)
 
 
 def test_index_get_indexer_non_unique() -> None: