How to use the react-lightning-design-system.FieldSet.Row function in react-lightning-design-system

import React, { Component } from 'react';
import moment from 'moment';
import {
  Button, Form, Input, Textarea, RadioGroup, Radio,
  CheckboxGroup, Checkbox, Select, Option,
  Picklist, PicklistItem, Icon,
  DateInput,
  Lookup,
  FieldSet,
} from 'react-lightning-design-system';

const Row = FieldSet.Row;


const LOOKUP_DATA = [
  { label: 'Account', value: '1', icon: 'standard:account' },
  { label: 'Contact', value: '2', icon: 'standard:contact' },
  { label: 'Opportunity', value: '3', icon: 'standard:opportunity' },
];

const TodayButtonExtensionRenderer = (props) => {
  const { onSelect } = props; // eslint-disable-line react/prop-types
  const today = moment().format('YYYY-MM-DD');
  return (
    <div style="{{">
      <button> onSelect(today) }</button></div>

import React from 'react';
import { Form, FieldSet, Lookup, Button } from 'react-lightning-design-system';

import COMPANIES from './data/COMPANIES';
import OPPORTUNITIES from './data/OPPORTUNITIES';
import CAMPAIGNS from './data/CAMPAIGNS';
import CASES from './data/CASES';
import SCOPES from './data/SCOPES';

const Row = FieldSet.Row;

const COMPANY_DATA = COMPANIES.map((label, i) => ({
  icon: 'standard:account',
  label,
  value: `10000${i}`,
  scope: 'Account',
}));

const OPP_DATA = COMPANIES.map((label, i) => ({
  icon: 'standard:opportunity',
  label: `${label} - ${OPPORTUNITIES[i % OPPORTUNITIES.length]}`,
  value: `20000${i}`,
  scope: 'Opportunity',
}));

const CAMPAIGN_DATA = CAMPAIGNS.map((label, i) => ({