docs: def installed(name, nodataset=False, brand_opts=None):
      '''
      Ensure zone is installed
  
      name : string
          name of the zone
      nodataset : boolean
          do not create a ZFS file system
      brand_opts : boolean
          brand specific options to pass
  
      '''
      ret = {'name': name,
             'changes': {},
             'result': None,
             'comment': ''}
  
      zones = __salt__['zoneadm.list'](installed=True, configured=True)
      if name in zones:
          if zones[name]['state'] == 'configured':
              if __opts__['test']:
                  res_install = {'status': True}
              else:
                  res_install = __salt__['zoneadm.install'](name, nodataset, brand_opts)
              ret['result'] = res_install['status']
              if ret['result']:
                  ret['changes'][name] = 'installed'
                  ret['comment'] = 'The zone {0} was installed.'.format(name)
              else:
                  ret['comment'] = []
                  ret['comment'].append('Failed to install zone {0}!'.format(name))
                  if 'message' in res_install:
                      ret['comment'].append(res_install['message'])
                  ret['comment'] = "\n".join(ret['comment'])
          else:
              ret['result'] = True
              ret['comment'] = 'zone {0} already installed.'.format(name)
      else:
          ret['result'] = False
          ret['comment'] = 'zone {0} is not configured!'.format(name)
  
      return ret