fix tests and stuffs

lib/src/utils/device_keys_list.dart

@@ -113,9 +113,7 @@ abstract class _SignedKey {
   }
 
   bool hasValidSignatureChain({Set<String> visited}) {
-    if (visited == null) {
+    visited ??= <String>{};
-      visited = Set<String>();
-    }
     final setKey = '${userId};${identifier}';
     if (visited.contains(setKey)) {
       return false; // prevent recursion

test/client_test.dart

@@ -601,7 +601,7 @@ void main() {
               'dSO80A01XiigH3uBiDVx/EjzaoycHcjq9lfQX0uWsqxl2giMIiSPR8a4d291W1ihKJL/a+myXS367WT6NAIcBA'
         }
       }
-    });
+    }, matrix);
     test('startOutgoingOlmSessions', () async {
       expect(matrix.olmSessions.length, 0);
       if (olmEnabled) {

test/device_keys_list_test.dart

@@ -56,21 +56,21 @@ void main() {
       };
 
       var userDeviceKeys = <String, DeviceKeysList>{
-        '@alice:example.com': DeviceKeysList.fromJson(rawListJson),
+        '@alice:example.com': DeviceKeysList.fromJson(rawListJson, null),
       };
       var userDeviceKeyRaw = <String, dynamic>{
         '@alice:example.com': rawListJson,
       };
 
-      expect(json.encode(DeviceKeys.fromJson(rawJson).toJson()),
+      expect(json.encode(DeviceKeys.fromJson(rawJson, null).toJson()),
           json.encode(rawJson));
-      expect(json.encode(DeviceKeysList.fromJson(rawListJson).toJson()),
+      expect(json.encode(DeviceKeysList.fromJson(rawListJson, null).toJson()),
           json.encode(rawListJson));
 
       var mapFromRaw = <String, DeviceKeysList>{};
       for (final rawListEntry in userDeviceKeyRaw.entries) {
         mapFromRaw[rawListEntry.key] =
-            DeviceKeysList.fromJson(rawListEntry.value);
+            DeviceKeysList.fromJson(rawListEntry.value, null);
       }
       expect(mapFromRaw.toString(), userDeviceKeys.toString());
     });

test_driver/famedlysdk_test.dart

@@ -109,7 +109,7 @@ void test() async {
   assert(!testClientB
       .userDeviceKeys[testUserA].deviceKeys[testClientA.deviceID].blocked);
   await testClientA.userDeviceKeys[testUserB].deviceKeys[testClientB.deviceID]
-      .setVerified(true, testClientA);
+      .setVerified(true);
 
   print('++++ Check if own olm device is verified by default ++++');
   assert(testClientA.userDeviceKeys.containsKey(testUserA));