anchor.diff:  
   -behaviour(gen_component).
   
  --export([dump_node_states/0, kill_nodes/1, register_dht_node/1, deregister_dht_node/1]).
  +-export([dump_node_states/0, kill_nodes/1, kill_nodes_by_name/1, register_dht_node/1, 
  +         deregister_dht_node/1]).
   
   -export([start_link/1, init/1, on/2]).
   
  
positive.code:     State;
  
  on({delete_node, SupPid, SupId}, State) ->
      sup:sup_terminate_childs(SupPid),
      _ = supervisor:terminate_child(main_sup, SupId),
      _ = supervisor:delete_child(main_sup, SupId),
      State;
  
  on({add_node, Options}, State) ->
  
negative.code:              _ = supervisor:terminate_child(main_sup, Id),
               supervisor:delete_child(main_sup, Id)
           end || Child <- Childs],
      ok.
  
  % @doc kills Scalaris nodes from the current VM 
  -spec kill_nodes_by_name(Names::list(pid_groups:groupname())) -> ok.
  kill_nodes_by_name(Names) ->
      comm:send_local(service_per_vm, {kill_nodes_by_name, Names}),
      ok.
  
  %% @doc Sends a register message to a running service_per_vm to register a
  