code: public AccountBalance getAccountBalance(final String accountCode) {
          return doGET(Account.ACCOUNT_RESOURCE + "/" + accountCode + AccountBalance.ACCOUNT_BALANCE_RESOURCE, AccountBalance.class);
      }
docs: Get Account Balance
  <p>
  Retrieves the remaining balance on the account
  
  @param accountCode recurly account id
  @return the updated AccountBalance if success, null otherwise