How to use the reason-react/lib/es6/src/ReasonReact.js.reducerComponent function in reason-react

// Generated by BUCKLESCRIPT VERSION 2.2.3, PLEASE EDIT WITH CARE

import * as Menu from "./Menu.js";
import * as Block from "bs-platform/lib/es6/block.js";
import * as Curry from "bs-platform/lib/es6/curry.js";
import * as React from "react";
import * as Header from "./Header.js";
import * as Popover from "./Popover.js";
import * as Calendar from "./Calendar.js";
import * as Electron from "electron";
import * as ReasonReact from "reason-react/lib/es6/src/ReasonReact.js";
import * as Add_months from "date-fns/add_months";
import * as Sub_months from "date-fns/sub_months";

var component = ReasonReact.reducerComponent("Index");

var container_styles = {
  height: "100%"
};

var caret_styles = {
  borderRight: "solid transparent 10px",
  borderBottom: "solid #000 10px",
  borderLeft: "solid transparent 10px",
  content: "' '",
  height: "10px",
  left: "50%",
  marginLeft: "-10px",
  position: "absolute",
  top: "0",
  width: "0"