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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def writelines_nl(fileobj: TextIO, lines: Iterable[str]) -> None: """ Writes lines, plus terminating newline characters, to the file. http://stackoverflow.com/questions/13730107/writelines-writes-lines-without-newline-just-fills-the-file) """
  # noqa
    fileobj.write('\n'.join(lines) + '\n')