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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 _maybe_read_file(filename):
 """Read the given file, if it exists. Args: filename: A path to a file. Returns: A string containing the file contents, or `None` if the file does not exist. """

  try:
    with open(filename) as infile:
      return infile.read()
  except IOError as e:
    if e.errno == errno.ENOENT:
      return None