anchor.diff:       ?_assertEqual(<<"ABC DEF">>, trim(<<"  ABC DEF    ">>)),
        ?_assertEqual(<<"hello">>, to_lower(<<"HELlo">>)),
        ?_assertEqual(<<"HELLO">>, to_upper(<<"HELlo">>)),
  -     
  +
  +     % quoting
  +     ?_assertEqual(<<"\"va\\\\lue\"">>, quote_string(<<"va\\lue">>)),
  +
        % "is" tests
        ?_assertEqual(true, is_digit_char($5)),
        ?_assertEqual(false, is_digit_char($a)),
  
positive.code: 
  -spec binary_test_() -> list().
  binary_test_() ->
      [?_assertEqual(<<>>, trim_leading(<<>>)),
       ?_assertEqual(<<>>, trim_leading(<<"    ">>)),
       ?_assertEqual(<<"ABC DEF    ">>, trim_leading(<<"  ABC DEF    ">>)),
       ?_assertEqual(<<>>, trim_trailing(<<>>)),
  
negative.code:      ?_assertEqual(<<"some">>, any_to_binary(some)),
       ?_assertEqual(<<"some">>, any_to_binary(<<"some">>)),
       ?_assertEqual(<<"123">>, any_to_binary(123)),
       ?_assertEqual(<<"123.35">>, any_to_binary(123.35)),
       ?_assertEqual(<<"example.com">>, any_to_binary("example.com")),
       ?_assertEqual(<<"10.0.0.1">>, any_to_binary({10, 0, 0, 1})),
       ?_assertEqual(<<"example.com">>, addr_to_binary("example.com")),
       ?_assertEqual(<<"10.0.0.1">>, addr_to_binary({10, 0, 0, 1})),
       ?_assertEqual(<<"[2001:0db8:11a3:09d7:1f34:8a2e:07a0:765d]">>, addr_to_binary({8193,3512,4515,2519,7988,35374,1952,30301})),
       ?_assertEqual(<<"neverexistingatom">>, binary_to_existing_atom(<<"neverexistingatom">>)),
       ?_assertEqual('existingatom', binary_to_existing_atom(<<"existingatom">>)),
  
  