public void init() {
    if (!initialized.getAndSet(true)) {
      processAccountJsonFile();

      // add the default unknown account
      ArrayList<Account> accounts = new ArrayList<>();
      accounts.add(UNKNOWN_ACCOUNT);

      try {
        updateAccounts(accounts);
      } catch (AccountServiceException e) {
        logger.warn("Unable to add default unknown account", e);
      }
    }
  }
Initializes this instance. Does all work which requires handing out references to this instance itself which can't
be done during normal instance construction without letting a reference to an incomplete constructed instance escape.
ambry-account/src/main/java/com/github/ambry/account/InMemoryAccountService.java