anchor.diff:              Value
       end.
   
  -%% TODO: move these API calls into the gen_server mechanism, so that we can
  -%% easily switch between common_test and stand-alone runs if we wish...
  -
   get_env() ->
       gen_server:call(?MODULE, list).
   
  
positive.code:         _ ->
              lists:keyreplace(K, 1, Existing, New)
      end;
  extend({environment, _}=New, Existing) ->
      [New|Existing];
  extend({environment, _, _}=New, Existing) ->
  
negative.code: merge(New, Existing) ->
      append_if_missing(fun lists:member/2, New, Existing).
  
  %% TODO: this head (clause) isn't used any more!?
  extend({Path, Spec}=New, Existing) when Path =:= dir orelse
                                          Path =:= file ->
      %% TODO: this isn't very flexible - make it simpler to use...
  