code: function pickBy(object, predicate) {
      return Object.keys(object).reduce(function (records, key) {
          var value = object[key];
          if (predicate(value, key)) {
              records[key] = value;
          }
          return records;
      }, {});
  }
docs: Creates an object composed of the object properties predicate returns
  truthy for. The predicate is invoked with two arguments: (value, key).