'Eats a vgc-cluster space-extend commandline to a dict.'

def _parse_space_extend(self, *cmd):

    self.extended = {'storageserver': ''}
    cmd = list(*cmd)
    while cmd:
        param = cmd.pop(0)
        if (param == '-n'):
            self.extended['name'] = cmd.pop(0)
        elif (param == '-s'):
            self.extended['size'] = cmd.pop(0)
        elif (param == '-S'):
            self.extended['storageserver'] += (cmd.pop(0) + ',')
        else:
            pass
    if self._fail_extend:
        raise processutils.ProcessExecutionError(exit_code=1)
    else:
        return ('', '')
