anchor.diff:  -export([
            testing/0,
            testing2/0,
  -         testing3/0
  +         testing3/0,
  +         testing4/0
           ]).
   
   -include("twilio.hrl").
  
positive.code: 
  testing3() ->
      DIAL = #dial{body=[#number{number="+4455222"}]},
      case is_valid([DIAL]) of
          false ->
              io:format("~p is not valid~n", [DIAL]);
          true  ->
              io:format("Does ~p validate? ~p~n",
                        [DIAL, validate([DIAL])]),
              compile([DIAL])
      end.
  
negative.code: 
  check_bool(undefined, _Fld, _Rec, Acc) ->
      Acc;
  check_bool(true, _Fld, _Rec, Acc) ->
      Acc;
  check_bool(false, _Fld, _Rec, Acc) ->
      Acc;
  check_bool(Val, Fld, Rec, Acc) ->
      [io_lib:format("Invalid ~p in ~p ~p~sn", [Fld, Rec, Val, "~"]) | Acc].
  
  check_int(undefined, _Min, _Fld, _Rec, Acc) ->
      Acc;
  