@Override
 @Before
 public void setUp() throws Exception {
   super.setUp(new MemoryBlockStore(UnitTestParams.get()));
   peerGroup.addWallet(wallet);
   // Fix the random permutation that TransactionBroadcast uses to shuffle the peers.
   TransactionBroadcast.random = new Random(0);
   peerGroup.setMinBroadcastConnections(2);
   peerGroup.startAndWait();
 }
 @After
 public void tearDown() throws Exception {
   super.tearDown();
   peerGroup.stopAndWait();
 }