anchor.diff:  
   
   mgr_get_node_pubkey(NodeName, #{nodes := Nodes}) ->
  -    #{NodeName := {Mod, NodeState}} = Nodes,
  +    {Mod, NodeState} = maps:get(NodeName, Nodes),
       Mod:get_node_pubkey(NodeState).
   
   mgr_extract_archive(NodeName, Path, Archive, #{nodes := Nodes} = State) ->
  
positive.code: handle_call({get_node_pubkey, NodeName}, _From, State) ->
      {reply, mgr_get_node_pubkey(NodeName, State), State};
  handle_call({get_service_address, NodeName, Service}, _From, #{nodes := Nodes} = State) ->
      #{NodeName := {Mod, NodeState}} = Nodes,
      ServiceAddress = Mod:get_service_address(Service, NodeState),
      {reply, ServiceAddress, State};
  handle_call({get_internal_address, NodeName, Service}, _From, #{nodes := Nodes} = State) ->
      #{NodeName := {Mod, NodeState}} = Nodes,
      ServiceAddress = Mod:get_internal_address(Service, NodeState),
      {reply, ServiceAddress, State};
  handle_call({get_config, NodeName, Path}, _From, #{nodes := Nodes} = State) when is_list(Path) ->
      #{NodeName := {_Mod, NodeState}} = Nodes,
      Config = maps:get(config, NodeState, []),
      {reply, config_find(Path, Config), State};
  handle_call({get_hostname, NodeName}, _From, #{nodes := Nodes} = State) ->
      #{NodeName := {_Mod, _NodeState}} = Nodes,
      %% for the moment only localhost supported
      {reply, "localhost", State};
  handle_call({start_node, NodeName}, _From, #{nodes := Nodes} = State) ->
  
negative.code:     NodeState2 = Mod:start_node(NodeState),
      {reply, ok, State#{nodes := Nodes#{NodeName := {Mod, NodeState2}}}};
  handle_call({stop_node, NodeName, Timeout}, _From, #{nodes := Nodes} =State) ->
      {Mod, NodeState} = maps:get(NodeName, Nodes),
      Opts = #{soft_timeout => Timeout},
      NodeState2 = Mod:stop_node(NodeState, Opts),
      {reply, ok, State#{nodes := Nodes#{NodeName := {Mod, NodeState2}}}};
  handle_call({kill_node, NodeName}, _From, #{nodes := Nodes} = State) ->
      {Mod, NodeState} = maps:get(NodeName, Nodes),
      NodeState2 = Mod:kill_node(NodeState),
      {reply, ok, State#{nodes := Nodes#{NodeName := {Mod, NodeState2}}}};
  handle_call({extract_archive, NodeName, Path, Archive}, _From, State) ->
  