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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 flush_all(self, delay=0, noreply=None):
 """ The memcached "flush_all" command. Args: delay: optional int, the number of seconds to wait before flushing, or zero to flush immediately (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
        cmd = b'flush_all ' + six.text_type(delay).encode('ascii')
        if noreply:
            cmd += b' noreply'
        cmd += b'\r\n'
        results = self._misc_cmd([cmd], b'flush_all', noreply)
        if noreply:
            return True
        return results[0] == b'OK'