anchor.diff:  %%------------------------------------------------------------------------------
   -spec register_cmd(atom(), {module(), atom()}, list()) -> true.
   register_cmd(Cmd, MF, Opts) ->
  -    ets:insert(?CMD_TAB, {Cmd, MF, Opts}).
  +    gen_server:cast(?SERVER, {register_cmd, Cmd, MF, Opts}).
   
   %%------------------------------------------------------------------------------
   %% @doc Unregister a command
  
positive.code: %%% SOFTWARE.
  %%%-----------------------------------------------------------------------------
  %%% @doc
  %%% emqttd control commands.
  %%%
  %%% @end
  %%%-----------------------------------------------------------------------------
  
negative.code: 
  -include("emqttd_cli.hrl").
  
  -behaviour(gen_server).
  
  -define(SERVER, ?MODULE).
  
  %% API Function Exports
  -export([start_link/0,
           register_cmd/3,
           unregister_cmd/1,
           run/1]).
  
  %% gen_server Function Exports
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
           terminate/2, code_change/3]).
  
  -record(state, {seq = 0}).
  
  -define(CMD_TAB, mqttd_ctl_cmd).
  
  