anchor.diff:      {reply, ok, St};
   handle_call({set_write_timeout, Timeout}, _From, St) ->
       {reply, ok, St#st{write_timeout = Timeout}};
  +handle_call(get_changes_pid, _From, St) ->
  +    {reply, {ok, St#st.changes_pid}, St};
   handle_call(_Call, _From, St) ->
       {noreply, St}.
   
  
positive.code: -export([for_db/1, for_db/2, for_docid/2, for_docid/3, get/3, local/1, fold/2]).
  -export([for_shard_name/1]).
  -export([set_max_size/1]).
  
  -record(st, {
      max_size = 25000,
  
negative.code: set_max_size(Size) when is_integer(Size), Size > 0 ->
      gen_server:call(?MODULE, {set_max_size, Size}).
  
  get_changes_pid() ->
      gen_server:call(?MODULE, get_changes_pid).
  
  handle_config_change("mem3", "shard_cache_size", SizeList, _, _) ->
      Size = list_to_integer(SizeList),
      {ok, gen_server:call(?MODULE, {set_max_size, Size}, infinity)};
  