code: private void initNewFile() throws IOException {
      mFile = new File(PathUtils.concatPath(CommonUtils.getTmpDir(mTmpDirs), UUID.randomUUID()));
      if (mHash != null) {
        mLocalOutputStream =
            new BufferedOutputStream(new DigestOutputStream(new FileOutputStream(mFile), mHash));
      } else {
        mLocalOutputStream = new BufferedOutputStream(new FileOutputStream(mFile));
      }
      mPartitionOffset = 0;
      LOG.debug("Init new temp file @ {}", mFile.getPath());
    }
docs: Creates a new temp file to write to.