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