anchor.diff:  
   filter_parse(Key, Parse) ->
       case lists:filter(fun(KV) ->
  -                              (Key == element(1, KV)) 
  +                              (Key == element(1, KV))
                                     andalso
                                       (element(2, KV) /= undefined)
                         end,
  
positive.code:                             {value, {_, Boundary}} =
                                  lists:keysearch(boundary, 1, LineArgs),
                              parse_multipart(
                                binary_to_list(un_partial(Arg#arg.clidata)), 
                                Boundary)
                      end;
                  _Other ->
  
negative.code:     case atom_to_list(A) of
          [$$|Rest] -> list_to_atom(Rest);
          _Other -> erlang:error({bad_ehtml_var_name, A})
      end.
  
  ehtml_expander_test() ->
      %% Expr is a template containing variables.
  