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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 load(cls, directory):
 """Load a Digest from a `.digest` file adjacent to the given directory. :return: A Digest, or None if the Digest did not exist. """

    read_file = maybe_read_file(cls._path(directory))
    if read_file:
      fingerprint, length = read_file.split(':')
      return Digest(fingerprint, int(length))
    else:
      return None