anchor.diff:      ok;
   
   set_active_file(Context, Filename) ->
  -    #state{const=Const} = State = erlang:get(Context),
  -    erlang:put(Context, State#state{active_file=Filename}),
  +    #state{const=Const} = State = load_state(Context),
  +    save_state(State#state{active_file=Filename}),
       ephp_const:set_bulk(Const, [
           {<<"__FILE__">>, Filename},
           {<<"__DIR__">>, filename:dirname(Filename)}
  
positive.code: 
  start_link(#state{ref=Ref}=State) when is_reference(Ref) ->
      {ok, Vars} = ephp_vars:start_link(),
      erlang:put(Ref, State#state{
          ref = Ref,
          vars = Vars
      }),
  
negative.code: resolve({global, GVars,_Line}, #state{
          global=GlobalCtx,
          vars=Vars}=State) ->
      #state{vars=GlobalVars} = load_state(GlobalCtx),
      lists:foreach(fun(GlobalVar) ->
          ephp_vars:ref(Vars, GlobalVar, GlobalVars, GlobalVar)
      end, GVars),
  