fixed unit tests

Author: sagnghos

tests/unit/test_database.py

@@ -3560,11 +3560,14 @@ def _next_nth_request(self):
 
 
 class _Instance(object):
-    def __init__(self, name, client=_Client(), emulator_host=None):
+    def __init__(
+        self, name, client=_Client(), emulator_host=None, experimental_host=None
+    ):
         self.name = name
         self.instance_id = name.rsplit("/", 1)[1]
         self._client = client
         self.emulator_host = emulator_host
+        self.experimental_host = experimental_host
 
 
 class _Backup(object):