docs: def get_network_instances(self, name=""):
          """ get_network_instances implementation for NX-OS """
  
          # command 'show vrf detail' returns all VRFs with detailed information
          # format: list of dictionaries with keys such as 'vrf_name' and 'rd'
          command = "show vrf detail"
          vrf_table_raw = self._get_command_table(command, "TABLE_vrf", "ROW_vrf")
  
          # command 'show vrf interface' returns all interfaces including their assigned VRF
          # format: list of dictionaries with keys 'if_name', 'vrf_name', 'vrf_id' and 'soo'
          command = "show vrf interface"
          intf_table_raw = self._get_command_table(command, "TABLE_if", "ROW_if")
  
          # create a dictionary with key = 'vrf_name' and value = list of interfaces
          vrf_intfs = defaultdict(list)
          for intf in intf_table_raw:
              vrf_intfs[intf["vrf_name"]].append(py23_compat.text_type(intf["if_name"]))
  
          vrfs = {}
          for vrf in vrf_table_raw:
              vrf_name = py23_compat.text_type(vrf.get("vrf_name"))
              vrfs[vrf_name] = {}
              vrfs[vrf_name]["name"] = vrf_name
  
              # differentiate between VRF type 'DEFAULT_INSTANCE' and 'L3VRF'
              if vrf_name == "default":
                  vrfs[vrf_name]["type"] = "DEFAULT_INSTANCE"
              else:
                  vrfs[vrf_name]["type"] = "L3VRF"
  
              vrfs[vrf_name]["state"] = {
                  "route_distinguisher": py23_compat.text_type(vrf.get("rd"))
              }
  
              # convert list of interfaces (vrf_intfs[vrf_name]) to expected format
              # format = dict with key = interface name and empty values
              vrfs[vrf_name]["interfaces"] = {}
              vrfs[vrf_name]["interfaces"]["interface"] = dict.fromkeys(
                  vrf_intfs[vrf_name], {}
              )
  
          # if name of a specific VRF was passed as an argument
          # only return results for this particular VRF
          if name:
              if name in vrfs.keys():
                  return {py23_compat.text_type(name): vrfs[name]}
              else:
                  return {}
          # else return results for all VRFs
          else:
              return vrfs