code: def cli(env, sortby, cpu, domain, datacenter, hostname, memory, network,
          hourly, monthly, tag, columns, limit):
      
  
      vsi = SoftLayer.VSManager(env.client)
      guests = vsi.list_instances(hourly=hourly,
                                  monthly=monthly,
                                  hostname=hostname,
                                  domain=domain,
                                  cpus=cpu,
                                  memory=memory,
                                  datacenter=datacenter,
                                  nic_speed=network,
                                  tags=tag,
                                  mask=columns.mask(),
                                  limit=limit)
  
      table = formatting.Table(columns.columns)
      table.sortby = sortby
      for guest in guests:
          table.add_row([value or formatting.blank()
                         for value in columns.row(guest)])
  
      env.fout(table)
docs: List virtual servers.