anchor.diff:          gen_node_server_start,
           gen_node_server_state_after_start,
           gen_node_server_state_during_work,
  -        gen_node_server_work
  +        gen_node_server_work,
  +        gen_node_server_state_after_work,
  +        gen_node_server_states
       ].
   
   init_per_suite(Config) ->
  
positive.code: %% Tests
  -export([gen_node_server_start/1]).
  -export([gen_node_server_state_after_start/1]).
  -export([gen_node_server_state_during_work/1]).
  -export([gen_node_server_work/1]).
  
  %% ============================================================================
  
negative.code:     ok = gen_node:become(ChildId, double_fun()),
      ok = gen_node:reset(ChildId),
      #{state := ready} = gen_node:get_state(ChildId).
  
  gen_node_server_states(_) ->
      {ok, ChildId1, _ChildRef1} = gen_node:start_server(),
      {ok, ChildId2, _ChildRef2} = gen_node:start_server(),
      ok = gen_node:become(ChildId2, double_fun()),
      States = gen_node:get_states(),
      {ChildId1, #{state := ready}} = lists:keyfind(ChildId1, 1, States),
      {ChildId2, #{state := working}} = lists:keyfind(ChildId2, 1, States).
  