anchor.diff:  new(Options) ->
     Access = proplists:get_value(access, Options, private),
     init_ets_store(Access).
  +
  +close(Store) ->
  +  destroy_ets_store(Store).
   
   -spec add_type(avro_type(), store()) -> store().
   
  
positive.code:     []             -> false;
      [{Name, Type}] -> {ok, Type}
    end.
  
  %%%===================================================================
  %%% Tests
  
negative.code: %% API
  -export([new/0]).
  -export([new/1]).
  -export([close/1]).
  -export([add_type/2]).
  -export([lookup_type/2]).
  -export([fold/3]).
  