anchor.diff:  %% Internal Function Definitions
   %% ------------------------------------------------------------------
   
  +do_get_heartbeating_nodes(GProcName) ->
  +    GProcKey = {n, l, GProcName},
  +    Pid = '_',
  +    Value = '_',
  +    MatchSpec = [{{GProcKey, Pid, Value}, [], ['$$']}],
  +
  +    Nodes = gproc:select(MatchSpec),
  +    [{{Org, NodeName}, Val} || [{_,_,{_, Org, NodeName}},_,Val] <- Nodes].
  +
  
positive.code: -export([start_link/0,
           get_or_create_process/2,
           get_process/1,
           get_heartbeating_nodes/1,
           mk_gproc_name/1,
           mk_gproc_addr/1]).
  
negative.code:         Pid -> Pid
      end.
  
  -spec get_heartbeating_nodes() -> list().
  get_heartbeating_nodes() ->
      do_get_heartbeating_nodes({heartbeat, '_', '_'}).
  
  -spec get_heartbeating_nodes(binary()) -> list().
  get_heartbeating_nodes(OrgId) when is_binary(OrgId) ->
      do_get_heartbeating_nodes({heartbeat, OrgId, '_'}).
  
  -spec mk_gproc_name(node_ref()) -> {'heartbeat', org_id(), node_name()}.
  mk_gproc_name({OrgId, NodeName}) when is_binary(OrgId) andalso is_binary(NodeName) ->
  