code: public static String getBranchIdentifier(IBAN iban) {
          int index = CountryCodes.indexOf(iban.getCountryCode());
          if (index > -1) {
              int data = BANK_CODE_BRANCH_CODE[index];
              int branchIdBegin = (data & BRANCH_IDENTIFIER_BEGIN_MASK) >>> BRANCH_IDENTIFIER_BEGIN_SHIFT;
              int branchIdEnd = (data & BRANCH_IDENTIFIER_END_MASK) >>> BRANCH_IDENTIFIER_END_SHIFT;
              return branchIdBegin != 0 ? iban.toPlainString().substring(branchIdBegin, branchIdEnd) : null;
          }
          return null;
      }
docs: Returns the branch identifier from the given IBAN, if available.
  @param iban an iban to evaluate. Cannot be null.
  @return the branch ID for this IBAN, or null if unknown.