### Body

Currently `start_date` is mandatory parameter.
For DAGs with `schedule=None` we can relax this requirement as no scheduling calculation needed so the `start_date` parameter isn't used.

### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
GCSPrefixBlobTrigger,
    GCSUploadSessionTrigger,
)
TEST_BUCKET = "TEST_BUCKET"
TEST_OBJECT = "TEST_OBJECT"
TEST_GCP_CONN_ID = "TEST_GCP_CONN_ID"
TEST_IMPERSONATION_CHAIN = ["ACCOUNT_1", "ACCOUNT_2", "ACCOUNT_3"]
TEST_PREFIX = "TEST_PREFIX"
TEST_DAG_ID = "unit_tests_gcs_sensor"
DEFAULT_DATE = datetime(2015, 1, 1)
MOCK_DATE_ARRAY = [datetime(2019, 2, 24, 12, 0, 0) - i * timedelta(seconds=10) for i in range(25)]
TEST_INACTIVITY_PERIOD = 5
TEST_MIN_OBJECTS = 1
@pytest.fixture()
def context():
    """
    Creates an empty context.
    """
    context = {"data_interval_end": datetime.utcnow()}
    yield context
def next_time_side_effect():
    """
    This each time this is called mock a time 10 seconds later
    than the previous call.
    """
    return MOCK_DATE_ARRAY.pop()
mock_time = mock.Mock(side_effect=next_time_side_effect)
class TestGoogleCloudStorageObjectSensor:
    @mock.patch("airflow.providers.google.cloud.sensors.gcs.GCSHook")
    def test_should_pass_argument_to_hook(self, mock_hook):