docs: def get_volume_connector(self, assigner_id):
          """Get connector information of the instance for attaching to volumes.
  
          Connector information is a dictionary representing the ip of the
          machine that will be making the connection, the name of the iscsi
          initiator and the hostname of the machine as follows::
  
              {
                  'zvm_fcp': fcp
                  'wwpns': [wwpn]
                  'host': host
              }
          """
  
          empty_connector = {'zvm_fcp': [], 'wwpns': [], 'host': ''}
  
          # init fcp pool
          self.fcp_mgr.init_fcp(assigner_id)
          fcp_list = self.fcp_mgr.get_available_fcp()
          if not fcp_list:
              errmsg = "No available FCP device found."
              LOG.warning(errmsg)
              return empty_connector
          wwpns = []
          for fcp_no in fcp_list:
              wwpn = self.fcp_mgr.get_wwpn(fcp_no)
              if not wwpn:
                  errmsg = "FCP device %s has no available WWPN." % fcp_no
                  LOG.warning(errmsg)
              else:
                  wwpns.append(wwpn)
  
          if not wwpns:
              errmsg = "No available WWPN found."
              LOG.warning(errmsg)
              return empty_connector
  
          inv_info = self._smtclient.get_host_info()
          zvm_host = inv_info['zvm_host']
          if zvm_host == '':
              errmsg = "zvm host not specified."
              LOG.warning(errmsg)
              return empty_connector
  
          connector = {'zvm_fcp': fcp_list,
                       'wwpns': wwpns,
                       'host': zvm_host}
          LOG.debug('get_volume_connector returns %s for %s' %
                    (connector, assigner_id))
          return connector