anchor.diff:    rs = undefined,
     type = undefined,
     me,
  -  max_pool,
  +  size :: integer(),
  +  max_overflow :: integer(),
     connect_to,
     socket_to,
     topology,
  
positive.code:     host = Host,
      port = Port,
      rs = ReplicaSet,
      max_pool = PoolSize,
      connect_to = ConnectTimeoutMS,
      socket_to = SocketTimeoutMS,
      topology_opts = TopologyOptions,
  
negative.code:   mc_monitor:start_link(Topology, self(), {Host, Port}, Topts, Wopts).
  
  %% @private
  init_pool(#state{host = Host, port = Port, size = Size, max_overflow = Overflow, worker_opts = Wopts}) ->
    WO = lists:append([{host, Host}, {port, Port}], Wopts),
    mc_pool_sup:start_pool(mc_worker, [{size, Size}, {max_overflow, Overflow}], WO).
  
  %% @private
  parse_seed(Addr) when is_binary(Addr) ->
  