code: public void commit() throws IOException {
          // assures we perform the close operation only once.
          if (open.compareAndSet(true, false)) {
              // flush & close
              fout.force(true);
              fout.close();
  
              // if the current file exists, and append is true, then append samples and remove temp file
              // otherwise write header and move tmp file to target
              boolean exists = Files.exists(target);
              if (logger.isInfoEnabled()) {
                  logger.info("Finishing recording ...... append: " + append + " exists: " + exists + " target:" + target);
              }
              if (append && exists) {
                  appendSamples(target, temp);
                  writeHeader(target);
                  Files.delete(temp);
              } else {
                  writeHeader(temp);
                  Files.move(temp, target, StandardCopyOption.REPLACE_EXISTING);
              }
          }
      }
docs: Commit this sink. Causes to prevent any further write operations, and commits temporary file to target. When this
  returns, Sink is done and cannot be used again.