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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 has_data_file(self, sha1hash):
 # type: (str) -> bool """Confirms the presence of the given file in the RO."""

        folder = os.path.join(self.folder, DATA, sha1hash[0:2])
        hash_path = os.path.join(folder, sha1hash)
        return os.path.isfile(hash_path)