docs: function (value) {
    if (typeof value === 'object' && value !== null) {
      if (_.size(value) <= 2
          && _.all(value, function (v, k) {
            return typeof k === 'string' && k.substr(0, 1) === '$';
          })) {
        for (var i = 0; i < builtinConverters.length; i++) {
          var converter = builtinConverters[i];
          if (converter.matchJSONValue(value)) {
            return converter.fromJSONValue(value);
          }
        }
      }
    }
    return value;
  }