use roundtrip method instead of explicit alternative

xarray/tests/test_backends.py

@@ -409,12 +409,8 @@ def test_zero_dimensional_variable(self) -> None:
 
     def test_write_store(self) -> None:
         expected = create_test_data()
-        with self.create_store() as store:
-            expected.dump_to_store(store)
-            # we need to cf decode the store because it has time and
-            # non-dimension coordinates
-            with xr.decode_cf(store) as actual:
-                assert_allclose(expected, actual)
+        with self.roundtrip(expected) as actual:
+            assert_identical(actual, expected)
 
     def check_dtypes_roundtripped(self, expected, actual):
         for k in expected.variables: