submodule syslog2 {
     yang-version 1;
     belongs-to "syslog1" {
         prefix "sys1";
     }

     import "syslog3" {
        prefix "sys3";
     }

     identity tunnel-type {
         base sys3:final-address-family;
     }

     identity ref-address-family {
         base sys3:final-address-family;
     }
}