code: function wrapParser(parser, postprocess) {
      if (!parser) {
        return null;
      }
  
      postprocess = postprocess || Lazy.identity;
  
      var parseMethod = typeof parser === 'function' ?
        parser :
        parser.parse;
  
      return {
        parse: function() {
          return postprocess(parseMethod.apply(parser, arguments));
        }
      };
    }
docs: Takes either a `{ parse }` object or an actual function and wraps it as a
  `{ parse }` object with an optional post-processing step.