### Question:
JsonRpc2_0Moac extends JsonRpc2_0Admin implements Moac { @Override public Observable<SyncingNotfication> syncingStatusNotifications() { return chain3jService.subscribe( new Request<>( "mc_subscribe", Arrays.asList("syncing"), chain3jService, McSubscribe.class), "mc_unsubscribe", SyncingNotfication.class ); } JsonRpc2_0Moac(Chain3jService chain3jService); @Override Request<?, PersonalImportRawKey> personalImportRawKey(
            String keydata, String password); @Override Request<?, BooleanResponse> personalLockAccount(String accountId); @Override Request<?, PersonalSign> personalSign(
            String message, String accountId, String password); @Override Request<?, PersonalEcRecover> personalEcRecover(
            String hexMessage, String signedMessage); @Override Request<?, MinerStartResponse> minerStart(int threadCount); @Override Request<?, BooleanResponse> minerStop(); Observable<PendingTransactionNotification> newPendingTransactionsNotifications(); @Override Observable<SyncingNotfication> syncingStatusNotifications();  }### Answer:
@Test public void testSyncingStatusNotifications() { moac.syncingStatusNotifications(); verify(webSocketClient).send(matches( "\\{\"jsonrpc\":\"2.0\",\"method\":\"mc_subscribe\"," + "\"params\":\\[\"syncing\"],\"id\":[0-9]{1,}}")); }