anchor.diff:  function Tuple2#(EthernetT, EthernetT) toEthernet(MetadataT meta);
      EthernetT data = defaultValue;
      EthernetT mask = defaultMask;
  -   data.etherType = fromMaybe(?, meta.etherType);
  +   data.etherType = fromMaybe(?, meta.ethernet$etherType);
      mask.etherType = 0;
      return tuple2(data, mask);
   endfunction
  
positive.code:   rule stop_fsm if (stop_wire);
      fsm_deparse_ethernet.abort;
    endrule
    method Action start();
       start_wire.send();
    endmethod
    method Action stop();
       stop_wire.send();
    endmethod
    interface deparse_ipv4 = toGet(deparse_ipv4_fifo);
  endmodule
  
  
negative.code: function Tuple2#(Ipv4T, Ipv4T) toIpv4(MetadataT meta);
     Ipv4T ipv4 = defaultValue;
     Ipv4T mask = defaultMask;
     ipv4.dstAddr = fromMaybe(?, meta.ipv4$dstAddr);
     mask.dstAddr = 0;
     return tuple2(ipv4, mask);
  endfunction
  
  