Sub-Class "checker" does not override all virtual methods of abstract superclass 'ovm_subscriber"

In reply to dave_59:

I have few questions on this topic
[edited out 2 questions]
3. Assume dsp_sequence_item has an a field named my_var, is it legal to write something like:

function void write (T t);
  $display("my variable %d", t.my_var);
endfunction

If this cannot be done then what is the option to access the variables of such a class?
Probably this question is also related to 2 above

Thanks