Update tests/test_utils_snapshot.py

tests/test_utils_snapshot.py

@@ -3,6 +3,7 @@ import sys
 import os
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
 from slic.utils.snapshot import *
+from slic.utils.registry import instances
 from unittest.mock import patch
 
 
@@ -24,6 +25,9 @@ class FakeAdjustable(Adjustable):
     def __str__(self):
         return str(self.name)
 
+    def set_target_value(self, value, *args, **kwargs):
+        return value
+
 
 def test_snapshot_excludes_internal_by_default():