anchor.diff:    catch edis_db:run(
       edis_db:process(0),
       #edis_command{cmd = <<"ZINTERSTORE">>, args = [?KEY, [{?KEY, 1.0}, {?KEY2, 1.0}], sum],
  -                  group = zsets, result_type = number}).+                  group = zsets, result_type = number}).
  +
  +-spec zrange_n([binary()]) -> [binary()].
  +zrange_n(_Keys) ->
  +  catch edis_db:run(
  +    edis_db:process(0),
  +    #edis_command{cmd = <<"ZRANGE">>, args = [?KEY, 0, 1], group = zsets, result_type = multi_bulk}).
  +
  +-spec zrange_m([binary()]) -> [binary()].
  +zrange_m([Key|_]) ->
  +  catch edis_db:run(
  +    edis_db:process(0),
  +    #edis_command{cmd = <<"ZRANGE">>, args = [?KEY, 0, edis_util:binary_to_integer(Key)],
  +                  group = zsets, result_type = multi_bulk}).
  
positive.code:          init/0, init_per_testcase/1, init_per_round/2,
           quit/0, quit_per_testcase/1, quit_per_round/2]).
  -export([zadd/1, zadd_one/1, zcard/1, zcount_n/1, zcount_m/1, zincrby/1,
           zinterstore_min/1, zinterstore_n/1, zinterstore_k/1, zinterstore_m/1]).
  
  %% ====================================================================
  %% External functions
  
negative.code: init_per_round(Fun, Keys) when Fun =:= zcard;
                                 Fun =:= zadd_one;
                                 Fun =:= zcount_n;
                                 Fun =:= zincrby;
                                 Fun =:= zrange_n ->
    zadd(Keys),
    ok;
  init_per_round(Fun, Keys) when Fun =:= zinterstore_min ->
  