code: public void completeLocalOutput(Path fsOutputFile, Path tmpLocalFile)
      throws IOException {
      fs.completeLocalOutput(fsOutputFile, tmpLocalFile);
    }
docs: Called when we're all done writing to the target.  A local FS will
  do nothing, because we've written to exactly the right place.  A remote
  FS will copy the contents of tmpLocalFile to the correct target at
  fsOutputFile.