anchor.diff:  
   zadd(Config) ->
   	{client,Client} = lists:keyfind(client, 1, Config),
  +	ERR_NUM_ARGS = ?ERR_NUM_ARGS(<<"ZADD">>),
   	%% basic ZADD and score update
   	true = erldis_client:sr_scall(Client,[<<"zadd">>,<<"ztmp">>,10,<<"x">>]),
   	true = erldis_client:sr_scall(Client,[<<"zadd">>,<<"ztmp">>,20,<<"y">>]),
  
positive.code: 
  -define(ERR_NUM_ARGS(Command), {error,<<"ERR wrong number of arguments for '",Command/binary,"' command">>}).
  -define(ERR_NOTDOUBLE, {error,<<"ERR value is not a double">>}).
  -define(ERR_SINTAX, {error,<<"ERR syntax error">>}).
  
  all() -> [zadd,zincrby,zcard].
  
  init_per_suite(Config) ->
  	{ok,Client} = connect_erldis(10),
  
negative.code: init_per_testcase(_TestCase,Config) ->
  	{client,Client} = lists:keyfind(client, 1, Config),
  	erldis_client:sr_scall(Client,[<<"flushdb">>]),
  	erldis_client:sr_scall(Client,[<<"set">>,<<"string">>,<<"I am not a sorted set">>]),
  	Config.
  
  end_per_suite(_Config) ->
  