private void createSampleFile(File file, int size) throws IOException {
    try (FileOutputStream fos = new FileOutputStream(file)) {
      fos.write(new byte[size]);
    }
  }
Creates a sample file with the given size.
@param file the file to create.
@param size the size of the file in bytes.
@throws IOException if an I/O error occurs.
ambry-file-transfer/src/test/java/com/github/ambry/filetransfer/handler/StoreFileCopyHandlerIntegTest.java