   module ietf-network {
     yang-version 1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-network";
     prefix nd;

     container networks {
         container network-types {
           description
             "Serves as an augmentation target.
              The network type is indicated through corresponding
              presence containers augmented into this container.";
         }
     }
}