code: function fromJSGreedy(js) {
    return isImmutableConvertibleValue(js) ? js :
      Array.isArray(js) ?
        Immutable.Seq(js).map(fromJSGreedy).toList() :
        Immutable.Seq(js).map(fromJSGreedy).toMap();
  }
docs: From https://github.com/facebook/immutable-js/wiki/Converting-from-JS-objects#custom-conversion