code: private static File createSampleFile() throws IOException {
          File file = File.createTempFile("aws-java-sdk-", ".txt");
          file.deleteOnExit();
  
          Writer writer = new OutputStreamWriter(new FileOutputStream(file));
          writer.write("abcdefghijklmnopqrstuvwxyz\n");
          writer.write("01234567890112345678901234\n");
          writer.write("!@#$%^&*()-=[]{};':',.<>/?\n");
          writer.write("01234567890112345678901234\n");
          writer.write("abcdefghijklmnopqrstuvwxyz\n");
          writer.close();
  
          return file;
      }
docs: Creates a temporary file with text data to demonstrate uploading a file
  to Amazon S3
  
  @return A newly created temporary file with text data.
  
  @throws IOException