%Error: t/t_class_extern_bad.v:9:16: Duplicate declaration of task: 'extern nodef'
    9 |    extern task nodef();   
      |                ^~~~~
        t/t_class_extern_bad.v:8:16: ... Location of original declaration
    8 |    extern task nodef();
      |                ^~~~~
%Error: t/t_class_extern_bad.v:8:16: definition not found for extern 'nodef'
    8 |    extern task nodef();
      |                ^~~~~
%Error: t/t_class_extern_bad.v:9:16: definition not found for extern 'nodef'
    9 |    extern task nodef();   
      |                ^~~~~
%Error: t/t_class_extern_bad.v:12:6: extern not found that declares 'noproto'
   12 | task Base1::noproto();   
      |      ^~~~~
%Error: Exiting due to