code: public boolean hasRelativeLockTime() {
          if (version < 2)
              return false;
          for (TransactionInput input : getInputs())
              if (input.hasRelativeLockTime())
                  return true;
          return false;
      }
docs: A transaction has a relative lock time
  (<a href="https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki">BIP 68</a>) if it is version 2 or
  higher and at least one of its inputs has its {@link TransactionInput#SEQUENCE_LOCKTIME_DISABLE_FLAG} cleared.