anchor.diff:  -include_lib("eunit/include/eunit.hrl").
   -endif.
   
  --export_type([vclock/0, timestamp/0, vclock_node/0]).
  +-export_type([vclock/0, timestamp/0, vclock_node/0, dot/0]).
   
   -opaque vclock() :: [vc_entry()].
  +-opaque dot() :: vc_entry().
  +
   % The timestamp is present but not used, in case a client wishes to inspect it.
   -type vc_entry() :: {vclock_node(), {counter(), timestamp()}}.
   
  
positive.code:     case lists:keyfind(Node, 1, VClock) of
  	{_, {_Ctr, TS}} -> TS;
  	false           -> undefined
      end.
  
  % @doc Increment VClock at Node.
  
negative.code:          merge/1,
           get_counter/2,
           get_timestamp/2,
           get_entry/2,
           increment/2,
           increment/3,
           all_nodes/1,
  