anchor.diff:  unsubscribe() ->
       Nodes = get_all_nodes(),
       [unsubscribe(N) || N <- Nodes],
  -    dynamic_sub(false).
  +    disable_dynamic_sub().
   
   %% @doc Removes calling process from `Node' tracer's subscribers list.
   -spec unsubscribe(Node :: atom() | default_node) -> ok.
  
positive.code: subscribe() ->
      Nodes = get_all_nodes(),
      [subscribe(N) || N <- Nodes],
      dynamic_sub(true).
  
  %% @doc Adds calling process to `Node' tracer's subscribers list.
  -spec subscribe(Node :: atom() | default_node) -> ok.
  
negative.code:     [{node, Node}] = lookup(node),
      Node.
  
  enable_dynamic_sub() ->
      epl_subs_manager:enable_dynamic_sub(self()).
  
  disable_dynamic_sub() ->
      epl_subs_manager:disable_dynamic_sub(self()).
  