anchor.diff:  -export([parse_accept_encoding/1]).
   -export([parse_accept_language/1]).
   -export([parse_age/1]).
  +-export([parse_allow/1]).
   -export([parse_cache_control/1]).
   -export([parse_connection/1]).
   -export([parse_content_encoding/1]).
  
positive.code: 		<<"4.17">>
  	],
  	[{V, fun() -> {'EXIT', _} = (catch parse_age(V)) end} || V <- Tests].
  -endif.
  
  %% @doc Parse the Cache-Control header.
  
negative.code: %% Only return if the list is not empty.
  nonempty(L) when L =/= [] -> L.
  
  %% Parse a list of case sensitive tokens.
  token_list(<<>>, Acc) -> lists:reverse(Acc);
  token_list(<< $\s, R/bits >>, Acc) -> token_list(R, Acc);
  token_list(<< $\t, R/bits >>, Acc) -> token_list(R, Acc);
  token_list(<< $,, R/bits >>, Acc) -> token_list(R, Acc);
  token_list(<< C, R/bits >>, Acc) when ?IS_TOKEN(C) -> token(R, Acc, << C >>).
  
  token(<<>>, Acc, T) -> lists:reverse([T|Acc]);
  token(<< $\s, R/bits >>, Acc, T) -> token_list_sep(R, [T|Acc]);
  token(<< $\t, R/bits >>, Acc, T) -> token_list_sep(R, [T|Acc]);
  token(<< $,, R/bits >>, Acc, T) -> token_list(R, [T|Acc]);
  token(<< C, R/bits >>, Acc, T) when ?IS_TOKEN(C) -> token(R, Acc, << T/binary, C >>).
  
  token_list_sep(<<>>, Acc) -> lists:reverse(Acc);
  token_list_sep(<< $\s, R/bits >>, Acc) -> token_list_sep(R, Acc);
  token_list_sep(<< $\t, R/bits >>, Acc) -> token_list_sep(R, Acc);
  token_list_sep(<< $,, R/bits >>, Acc) -> token_list(R, Acc).
  
  %% Parse a list of case insensitive tokens.
  token_ci_list(<<>>, Acc) -> lists:reverse(Acc);
  token_ci_list(<< $\s, R/bits >>, Acc) -> token_ci_list(R, Acc);
  