anchor.diff:      init/1,
       is_bool/2,
       print_r/2,
  -    print_r/3
  +    print_r/3,
  +    isset/2,
  +    empty/2
   ]).
   
   -include("ephp.hrl").
  
positive.code:     ephp_context:set_output(Context, <<"Array\n(\n", Data/binary, ")\n">>),
      null.
  
  %% ----------------------------------------------------------------------------
  %% Internal functions
  %% ----------------------------------------------------------------------------
  
negative.code: 
  init(Context) ->
      Funcs = [
          is_bool, print_r, isset, empty
      ],
      lists:foreach(fun(Func) ->
          Name = atom_to_binary(Func, utf8),
  