anchor.diff:  
   start_throttle_process(Name, Interval, Rate) ->
       {ok, Pid} = amoc_throttle_process:start(Name, Interval, Rate),
  -    pg2:join(Name, Pid).
  +    pg:join(Name, Pid).
   
   update_throttle_processes([Pid], Interval, Rate, 1) ->
       amoc_throttle_process:update(Pid, Interval, Rate);
  
positive.code: 
  -spec start_processes(name(), pos_integer(), non_neg_integer(), pos_integer()) -> pos_integer().
  start_processes(Name, Rate, Interval, NoOfProcesses) ->
      pg2:create(Name),
      % Master metrics
      amoc_metrics:init(gauge, ?RATE(Name)),
      [amoc_metrics:init(counters, E) || E <- [?EXEC_RATE(Name), ?REQ_RATE(Name)]],
  
negative.code: -spec(start_link() ->
      {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
  start_link() ->
      pg:start_link(),
      gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
  
  -spec(ensure_throttle_processes_started(name(), non_neg_integer(),
  