code: function formatError(err, options) {
      options = options || {};
      var name = err.name || err.constructor.name;
      var str = util.format('%s: %s\n', name, err.message);
      if (err.buffer && err.buffer.hexdump) {
          str += err.buffer.hexdump({
              colored: options.color,
              boldStart: false,
              highlight: options.color ? errorHighlighter(err, options) : null
          });
      } else if (Buffer.isBuffer(err.buffer)) {
          if (options.color) {
              str += formatBufferColored(err, options);
          } else {
              str += formatBufferUncolored(err, options);
          }
      }
      return str;
  }
docs: istanbul ignore next TODO