<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def version(self):
 """Get the version of MongoDB that this Server runs as a tuple."""

        if not self.__version:
            command = (self.name, '--version')
            logger.debug(command)
            stdout, _ = subprocess.Popen(
                command, stdout=subprocess.PIPE).communicate()
            version_output = str(stdout)
            match = re.search(self.version_patt, version_output)
            if match is None:
                raise ServersError(
                    'Could not determine version of %s from string: %s'
                    % (self.name, version_output))
            version_string = match.group('version')
            self.__version = tuple(map(int, version_string.split('.')))
        return self.__version