Account implements TransactionBuilderAccount { public void incrementSequenceNumber() { mSequenceNumber++; } Account(KeyPair keypair, Long sequenceNumber); @Override KeyPair getKeypair(); @Override Long getSequenceNumber(); @Override Long getIncrementedSequenceNumber(); void incrementSequenceNumber();  }
@Test public void testIncrementSequenceNumber() { Account account = new Account(KeyPair.random(), 100L); account.incrementSequenceNumber(); assertEquals(account.getSequenceNumber(), new Long(101L)); }