anchor.diff:      IsKnownType =
           case wrq:get_req_header("content-type", ReqData) of
               "application/json" -> true;
  -            "application/protobuf" -> true;
  +            "application/x-protobuf" -> true;
               % allow content-type to be undefined when the body is empty
               'undefined' when IsEmptyBody -> true;
               _ -> false
  
positive.code: % Utility functions
  %
  
  format_to_content_type('pb') -> "application/protobuf";
  format_to_content_type('json') -> "application/json";
  format_to_content_type('piq') -> "text/plain".
  
  
  content_type_to_format("application/protobuf") -> 'pb';
  content_type_to_format("application/json") -> 'json';
  content_type_to_format("text/plain") -> 'piq';
  content_type_to_format(_) -> 'undefined'.
  
negative.code: %-define(DEBUG, 1).
  -include("debug.hrl").
  
  
  % XXX: set charset=UTF-8 in "Content-Type" response header for text (Piq), Json
  % and XML responses?
  