@Test
 public void empty() throws Exception {
   // Check the base case of a wallet with one key and no transactions.
   Wallet wallet1 = roundTrip(myWallet);
   assertEquals(0, wallet1.getTransactions(true).size());
   assertEquals(Coin.ZERO, wallet1.getBalance());
   assertArrayEquals(
       myKey.getPubKey(), wallet1.findKeyFromPubHash(myKey.getPubKeyHash()).getPubKey());
   assertArrayEquals(
       myKey.getPrivKeyBytes(),
       wallet1.findKeyFromPubHash(myKey.getPubKeyHash()).getPrivKeyBytes());
   assertEquals(
       myKey.getCreationTimeSeconds(),
       wallet1.findKeyFromPubHash(myKey.getPubKeyHash()).getCreationTimeSeconds());
   assertEquals(mScriptCreationTime, wallet1.getWatchedScripts().get(0).getCreationTimeSeconds());
   assertEquals(1, wallet1.getWatchedScripts().size());
   assertEquals(
       ScriptBuilder.createOutputScript(myWatchedKey.toAddress(params)),
       wallet1.getWatchedScripts().get(0));
   assertEquals(WALLET_DESCRIPTION, wallet1.getDescription());
 }