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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 read_string(cls, string):
 """Decodes a given bencoded string or bytestring. Returns decoded structure(s). :param str string: :rtype: list """

        if PY3 and not isinstance(string, byte_types):
            string = string.encode()

        return cls.decode(string)