Index: tests/conftest.py
===================================================================
--- tests/conftest.py	(revision 753855acf7e2fe3b419275ead16f408dff1a4514)
+++ tests/conftest.py	(revision ea28ca0608ed52526793cd6fea857763cf9a41ba)
@@ -33,6 +33,7 @@
 
 @pytest.fixture
-def sample_domain_manager():
-    return DomainManager(CompositeBackend(Domain), EntityRegistry())
+def sample_domain_manager(backend):
+    return DomainManager(CompositeBackend(authoritative_backend=backend,
+                                          sync_backends=None), EntityRegistry())
 
 # ─────────────────────────────────────────────────────────────
Index: tests/test_composite_backend.py
===================================================================
--- tests/test_composite_backend.py	(revision 753855acf7e2fe3b419275ead16f408dff1a4514)
+++ tests/test_composite_backend.py	(revision ea28ca0608ed52526793cd6fea857763cf9a41ba)
@@ -8,5 +8,5 @@
     secondary = InMemoryBackend(Domain)
 
-    backend = CompositeBackend(Domain, primary, secondary)
+    backend = CompositeBackend(authoritative_backend=primary, sync_backends=[secondary])
 
     backend.save(sample_domain)
@@ -23,5 +23,5 @@
     secondary = InMemoryBackend(Domain)
 
-    backend = CompositeBackend(Domain, primary, secondary)
+    backend = CompositeBackend(authoritative_backend=primary, sync_backends=[secondary])
 
     primary.save(sample_domain)
@@ -37,5 +37,5 @@
     secondary = InMemoryBackend(Domain)
 
-    backend = CompositeBackend(Domain, primary, secondary)
+    backend = CompositeBackend(authoritative_backend=primary, sync_backends=[secondary])
 
     backend.save(sample_domain)
Index: tests/test_persistance_integrity.py
===================================================================
--- tests/test_persistance_integrity.py	(revision 753855acf7e2fe3b419275ead16f408dff1a4514)
+++ tests/test_persistance_integrity.py	(revision ea28ca0608ed52526793cd6fea857763cf9a41ba)
@@ -49,5 +49,4 @@
     file = tmp_path / "question.json"
     json_str = approved_domain.to_json()
-    print("JSON", json_str)
     file.write_text(json_str)