### Question:
JsonAccountService extends AbstractAccountService { @Override public boolean updateAccounts(Collection<Account> accounts) { throw new UnsupportedOperationException( "Service does not support updating of accountsById via API. Modify account JSON files on all nodes instead."); } JsonAccountService(Path accountFile, AccountServiceMetrics accountServiceMetrics, ScheduledExecutorService scheduler,
      JsonAccountConfig accountConfig); @Override boolean updateAccounts(Collection<Account> accounts); @Override void close(); void processAccountJsonFile();  }### Answer:
@Test(expected = UnsupportedOperationException.class) public void testUpdateAccounts() throws Exception { accountService.updateAccounts(Collections.emptyList()); }