anchor.diff:  				     end, CT, vector_orddict:to_list(PrunedSnapshots)),
   	    {Key,Length,OpId,ListLen,OpsDict} = case ets:lookup(OpsCache, Key) of
   						    [] ->
  -							{Key, 0, 0, 0, []};
  +							{Key, 0, 0, 0, {}};
   						    [Tuple] ->
  -							tuple_to_key(Tuple,true)
  +							tuple_to_key(Tuple,false)
   						end,
               {NewLength,PrunedOps}=prune_ops({Length,OpsDict}, CommitTime),
               true = ets:insert(SnapshotCache, {Key, PrunedSnapshots}),
  
positive.code: 	 get_cache_name/2,
  	 store_ss/3,
           update/2,
  	 belongs_to_snapshot_op/3]).
  
  %% Callbacks
  
negative.code:     Acc;
  tuple_to_key_int(Next,Last,Tuple,Acc) ->
      tuple_to_key_int(Next+1,Last,Tuple,[element(Next,Tuple)|Acc]).
  
  %% @doc Insert an operation and start garbage collection triggered by writes.
  %% the mechanism is very simple; when there are more than OPS_THRESHOLD
  