anchor.diff:                                             [#edis_command{cmd = <<"APPEND">>,
                                                             args = [<<"test-string">>, <<"X">>],
                                                             result_type = number,
  -                                                          group = strings} || _Key <- Keys]
  -                            ]}),
  +                                                          group = strings} || _Key <- Keys]]}),
     case Deleted of
       0 -> ok;
       1 -> ok
  
positive.code: -export([all/0,
           init/0, init_per_testcase/1, init_per_round/2,
           quit/0, quit_per_testcase/1, quit_per_round/2]).
  -export([append/1, decr/1, decrby/1]).
  
  %% ====================================================================
  %% External functions
  
negative.code:     #edis_command{cmd = <<"APPEND">>, args = [<<"test-string">>, Key],
                    group = strings, result_type = number}).
  
  -spec decr([binary()]) -> integer().
  decr(_) ->
    edis_db:run(
      edis_db:process(0),
      #edis_command{cmd = <<"DECR">>, args = [<<"test-string">>],
                    group = strings, result_type = number}).
  
  -spec decrby([binary()]) -> integer().
  decrby(Keys) ->
    edis_db:run(
      edis_db:process(0),
      #edis_command{cmd = <<"DECRBY">>, args = [<<"test-string">>, length(Keys)],
                    group = strings, result_type = number}).
  
  -spec get([binary()]) -> binary().
  get(_) ->
    edis_db:run(
      edis_db:process(0),
      #edis_command{cmd = <<"GET">>, args = [<<"test-string">>],
                    group = strings, result_type = bulk}).
  