code: private void applyMajorityWriteConcernToTransactionOptions() {
          if (transactionOptions != null) {
              WriteConcern writeConcern = transactionOptions.getWriteConcern();
              if (writeConcern != null) {
                  transactionOptions = TransactionOptions.merge(TransactionOptions.builder()
                          .writeConcern(writeConcern.withW("majority")).build(), transactionOptions);
              } else {
                  transactionOptions = TransactionOptions.merge(TransactionOptions.builder()
                          .writeConcern(WriteConcern.MAJORITY).build(), transactionOptions);
              }
          } else {
              transactionOptions = TransactionOptions.builder().writeConcern(WriteConcern.MAJORITY).build();
          }
      }
docs: Apply majority write concern if the commit is to be retried.