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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 version(self, conn):
 """Current version of the server. :return: ``bytes``, memcached version for current the server. """


        command = b'version\r\n'
        response = yield from self._execute_simple_command(
            conn, command)
        if not response.startswith(const.VERSION):
            raise ClientException('Memcached version failed', response)
        version, number = response.split()
        return number