Lambda code for the echo route

index.js

const AWS = require('aws-sdk');
// apply the patch
require('./patch.js');

let send = undefined;
function init(event) {
  const apigwManagementApi = new AWS.ApiGatewayManagementApi({
    apiVersion: '2018-11-29',
    endpoint: event.requestContext.domainName + '/' + event.requestContext.stage
  });
  send = async (connectionId, data) => {
    await apigwManagementApi.postToConnection({ ConnectionId: connectionId, Data: `Echo: ${data}` }).promise();
  }
}

exports.handler = async(event) => {
  init(event);
  const connectionId = event.requestContext.connectionId;
  let data = JSON.parse(event.body).data
  await send(connectionId, data);
  // the return value is ignored when this function is invoked from WebSocket gateway
  return {};
};

What is the purpose of the patch.js file and is it still needed today in your opinion?