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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 touch(self, key, expire=0, noreply=None):
 """ The memcached "touch" command. Args: key: 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 the expiration time was updated, False if the key wasn't found. """

        if noreply is None:
            noreply = self.default_noreply
        key = self.check_key(key)
        cmd = b'touch ' + key + b' ' + six.text_type(expire).encode('ascii')
        if noreply:
            cmd += b' noreply'
        cmd += b'\r\n'
        results = self._misc_cmd([cmd], b'touch', noreply)
        if noreply:
            return True
        return results[0] == b'TOUCHED'