anchor.diff:  %% ===================================================================
   
   
  -syntax() ->
  -    #{
  -        id => binary,
  -        conns => {list,
  -            #{
  -                url => binary,
  -                opts => nkpacket_syntax:safe_syntax(),
  -                weight => {integer, 0, 1000},
  -                pool => {integer, 1, 1000},
  -                refresh => boolean,
  -                headers => list,
  -                '__mandatory' => [url],
  -                '__defaults' => #{weigth=>100, pool=>1}
  -            }},
  -        debug => boolean,
  -        resolve_interval => {integer, 0, none}
  -    }.
  -
  -
   %% @doc
   -spec start_link(config()) ->
       {ok, pid()} | {error, term()}.
   
   start_link(Config) ->
  -    Syntax = syntax(),
  -    case nklib_syntax:parse(Config, Syntax) of
  -        {ok, Parsed, _} ->
  -           gen_server:start_link(?MODULE, [Parsed], []);
  -        {error, Error} ->
  -            {error, Error}
  -    end.
  +   gen_server:start_link(?MODULE, [Config], []).
   
   
   %% @doc
  
positive.code:                 pool => 3,
                  refresh => true
              }
  %%            #{
  %%                url => "https://microsoft.com",
  %%                opts => #{debug => true},
  %%                weight => 20
  %%            }
          ],
          debug => true,
          resolve_interval => 0
  
negative.code: 
  -record(state, {
      id :: term(),
      targets :: map(),
      conn_spec :: #{conn_id() => #conn_spec{}},
      conn_weight :: [{Start::integer(), Stop::integer(), conn_id()}],
      conn_status :: #{conn_id() => #conn_status{}},
  