anchor.diff:                 "", [{return, binary}]).
   
   %% @doc Canonicalize HTTP method as all uppercase binary
  +
   canonical_method(Method) ->
       list_to_binary(string:to_upper(binary_to_list(Method))).
   
  
positive.code: hash_file(F) ->
      hash_file(F, crypto:sha_init()).
  
  hash_file(F, Ctx) ->
      case io:get_chars(F, "", ?buf_size) of
          eof ->
  
negative.code: 
  %% @doc Canonicalize an HTTP request path by removing doubled slashes
  %% and trailing slash (except for case of root path).
  -spec  canonical_path(binary()) -> binary().
  canonical_path(Path = <<"/">>) ->
      Path;
  canonical_path(Path) ->
  