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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 is_prefix(cls, path):
 """ Check if a path is a valid prefix Args: path(str):
 path to be checked Returns: bool: True if the given path is a prefix """

        lagofile = paths.Paths(path).prefix_lagofile()
        return os.path.isfile(lagofile)