test(collection): add another non-existent test

Author: tharropoulos

tests/collections_test.py

@@ -305,4 +305,6 @@ def test_actual_contains(
     assert "companies" in actual_collections
 
     # Test for non-existing collection
-    assert "non_existent_collection" not in actual_collections
+    assert "non_existent_collection" not in actual_collections
+    # Test again
+    assert "non_existent_collection" not in actual_collections