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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 prepend(self, key, value, expire=0, noreply=None):
 """ The memcached "prepend" command. Args: key: str, see class docs for details. value: str, see class docs for details. expire: optional int, number of seconds until the item is expired from the cache, or zero for no expiry (the default). noreply: optional bool, True to not wait for the reply (defaults to self.default_noreply). Returns: True. """

        if noreply is None:
            noreply = self.default_noreply
        return self._store_cmd(b'prepend', {key: value}, expire, noreply)[key]