3.9 tests

Change-Id: I13e66016327aae0b0f3274e941bc615f379e5669

Author: MarkDaoust

tests/test_files.py

@@ -12,6 +12,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 from google.generativeai.types import file_types