anchor.diff:  -export([
            testing/0,
            testing2/0,
  -         testing3/0
  +         testing3/0,
  +         testing4/0
           ]).
   
   -include("twilio.hrl").
  
positive.code: 
  check_bool(undefined, _Fld, _Rec, Acc) ->
      Acc;
  check_bool(Val, Fld, Rec, Acc) ->
      case string:to_lower(Val) of
          "true" ->
              Acc;
          "false" ->
              Acc;
          _Other ->
              [io_lib:format("Invalid ~p in ~p ~p~sn", [Fld, Rec, Val, "~"]) | Acc]
      end.
  
  check_int(undefined, _Min, _Fld, _Rec, Acc) ->
      Acc;
  
negative.code: 
  testing3() ->
      DIAL = #dial{body=[#number{number="+4455222"}]},
      TwiML = [DIAL],
      case is_valid(TwiML) of
          false ->
              io:format("~p is not valid~n", [TwiML]);
          true  ->
              compile(TwiML)
      end.
  
  testing4() ->
      SAY      = #say{text = "burb"},
      PLAY     = #play{url = "some file"},
      REPEAT   = #repeat_EXT{},
      RESPONSE = #response_EXT{title = "berk", response = "1",
                                 body = [SAY, PLAY]},
      GATHER   = #gather{autoMenu_EXT = true, body = [SAY, PLAY],
                           after_EXT = [RESPONSE, REPEAT]},
  
      TwiML = [GATHER],
      validate(TwiML),
      case is_valid(TwiML) of
          false ->
              io:format("~p is not valid~n", [TwiML]);
          true  ->
              compile(TwiML)
      end.
  