The Illustrated Guide to Node.js - KCDC 2023

Node.js is a compelling platform for building all types of applications for startups to enterprises. Node.js strategically unites developers through the universal language of JavaScript. Or TypeScript! Why should you learn Node.js, and where do you start?

You will walk away from this fun introduction to Node.js having learned its strengths and the tools you need to be productive. We will cover a typical workflow of creating and debugging a web application. We'll also look at popular frameworks, libraries, and learning resources to give you the best start.

Transcript

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18. Why Node.js?
    • Rapid innovation & delivery
    • Developer happiness
    • Attract & retain talent
    • Performance
    “Why Node.js is Becoming the Go-To Technology in the Enterprise” – nearform.com
    

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19. Why Node.js?
    productivity
    satisfaction
    performance
    lower costs
    Improved results year-over-year
    Node.js Foundation User Survey
    

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23. • Backend API for SPAs, Mobile apps, etc.
    • “Serverless” computing
    • Real-time, streaming
    • WebSockets, push notifications
    • Chat, IM, social media
    Node.js Use Cases
    

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24. More than just backend
    • Automation Scripts (DevOps)
    • CLI tools (compile with nexe)
    • Microservices
    • Internet of Things
    • Desktop Apps
    

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25. Slack
    Visual Studio Code
    

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27. DevOps
    • Small footprint
    • Cross-platform
    • Event-driven
    • OSS tools
    • Containers
    

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34. Releases and Long-Term Support (LTS)
    

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38. Install Node.js
    https://nodejs.org
    

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39. Install Node.js with NVM
    Mac or Linux? Use nvm!
    https://github.com/nvm-sh/nvm
    Windows?
    Install Windows Subsytem for Linux (WSL)!
    > nvm install 18
    

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40. Install Node.js with NVM
    https://github.com/coreybutler/nvm-windows
    > nvm install 18
    

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41. What You Get
    > node –v
    v18.16.1
    > npm –v
    9.7.1
    

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42. > node –v
    v18.16.1
    > npm –v
    9.7.1
    What You Get
    

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43. First Things First!
    > mkdir myproject
    > cd myproject
    > npm init
    This utility will walk you through
    creating a package.json file...
    

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44. Install Dependencies
    > npm install axios
    > npm install --save-dev eslint
    > npm install -D eslint-config-reverentgeek
    

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45. const fs = require( "fs" ); // Built-in Node.js module
    const express = require( "express" ); // Module installed via npm
    const ApiService = require( "./app/ApiService" ); // Local module
    const api = new ApiService( { port: 8888 } );
    module-examples.js
    

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46. const fs = require( "fs" ); // Built-in Node.js module
    const express = require( "express" ); // Module installed via npm
    const ApiService = require( "./app/ApiService" ); // Local module
    const api = new ApiService( { port: 8888 } );
    module-examples.js
    

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47. const fs = require( "fs" ); // Built-in Node.js module
    const express = require( "express" ); // Module installed via npm
    const ApiService = require( "./app/ApiService" ); // Local module
    const api = new ApiService( { port: 8888 } );
    module-examples.js
    

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48. const fs = require( "fs" ); // Built-in Node.js module
    const express = require( "express" ); // Module installed via npm
    const ApiService = require( "./app/ApiService" ); // Local module
    const api = new ApiService( { port: 8888 } );
    module-examples.js
    

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49. const fs = require( "fs" ); // Built-in Node.js module
    const express = require( "express" ); // Module installed via npm
    const ApiService = require( "./app/ApiService" ); // Local module
    const api = new ApiService( { port: 8888 } );
    module-examples.js
    

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50. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Traditional Node-style callback
    api.methodWithACallback( "bacon", 42, function( err, results ) {
    if ( err ) {
    // Do something with the error
    console.log( err );
    return;
    }
    // Do stuff with results
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } );
    callback-example.js
    

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51. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Traditional Node-style callback
    api.methodWithACallback( "bacon", 42, function( err, results ) {
    if ( err ) {
    // Do something with the error
    console.log( err );
    return;
    }
    // Do stuff with results
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } );
    callback-example.js
    

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52. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Traditional Node-style callback
    api.methodWithACallback( "bacon", 42, function( err, results ) {
    if ( err ) {
    // Do something with the error
    console.log( err );
    return;
    }
    // Do stuff with results
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } );
    callback-example.js
    

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53. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Promise-style callback
    api.methodReturningAPromise( "bacon", 42 )
    .then( results => {
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } )
    .catch( err => {
    console.log( err );
    } );
    promise-example.js
    

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54. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Promise-style callback
    api.methodReturningAPromise( "bacon", 42 )
    .then( results => {
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } )
    .catch( err => {
    console.log( err );
    } );
    promise-example.js
    

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55. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Promise-style callback
    api.methodReturningAPromise( "bacon", 42 )
    .then( results => {
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } )
    .catch( err => {
    console.log( err );
    } );
    promise-example.js
    

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56. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Promise-style callback
    api.methodReturningAPromise( "bacon", 42 )
    .then( results => {
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } )
    .catch( err => {
    console.log( err );
    } );
    promise-example.js
    

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57. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Async-await callback
    async function doTheThing() {
    try {
    const users = await api.asyncMethodReturningUsers();
    const results = await api.methodReturningAPromise( "bacon", 42 );
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } catch( err ) {
    console.log( err );
    }
    }
    doTheThing();
    async-await-example.js
    

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58. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Async-await callback
    async function doTheThing() {
    try {
    const users = await api.asyncMethodReturningUsers();
    const results = await api.methodReturningAPromise( "bacon", 42 );
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } catch( err ) {
    console.log( err );
    }
    }
    doTheThing();
    async-await-example.js
    

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59. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Async-await callback
    async function doTheThing() {
    try {
    const users = await api.asyncMethodReturningUsers();
    const results = await api.methodReturningAPromise( "bacon", 42 );
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } catch( err ) {
    console.log( err );
    }
    }
    doTheThing();
    async-await-example.js
    

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60. const ApiService = require( "./app/ApiService" );
    const api = new ApiService( { port: 8888 } );
    // Async-await callback
    async function doTheThing() {
    try {
    const users = await api.asyncMethodReturningUsers();
    const results = await api.methodReturningAPromise( "bacon", 42 );
    for ( let i = 0; i < results.length; i++ ) {
    // stuff...
    }
    } catch( err ) {
    console.log( err );
    }
    }
    doTheThing();
    async-await-example.js
    

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61. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    

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62. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    

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63. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    

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64. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    

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65. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    const t = require( "./temperature" );
    const c = t.boilingCelsius;
    const f = t.convertToFahrenheit( c );
    console.log( `${ c } C is ${ f } F` );
    // output: 100 C is 212 F
    temp-example.js
    

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66. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    const t = require( "./temperature" );
    const c = t.boilingCelsius;
    const f = t.convertToFahrenheit( c );
    console.log( `${ c } C is ${ f } F` );
    // output: 100 C is 212 F
    temp-example.js
    

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67. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    const t = require( "./temperature" );
    const c = t.boilingCelsius;
    const f = t.convertToFahrenheit( c );
    console.log( `${ c } C is ${ f } F` );
    // output: 100 C is 212 F
    temp-example.js
    

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68. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    const t = require( "./temperature" );
    const c = t.boilingCelsius;
    const f = t.convertToFahrenheit( c );
    console.log( `${ c } C is ${ f } F` );
    // output: 100 C is 212 F
    temp-example.js
    

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69. function convertToCelsius( f ) {
    return ( f - 32 ) * ( 5 / 9 );
    }
    function convertToFahrenheit( c ) {
    return ( c * ( 9 / 5 ) ) + 32;
    }
    const temp = {
    freezingCelsius: 0,
    freezingFahrenheit: 32,
    boilingCelsius: 100,
    boilingFahrenheit: 212,
    convertToCelsius,
    convertToFahrenheit
    };
    module.exports = temp;
    temperature.js
    const t = require( "./temperature" );
    const c = t.boilingCelsius;
    const f = t.convertToFahrenheit( c );
    console.log( `${ c } C is ${ f } F` );
    // output: 100 C is 212 F
    temp-example.js
    

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70. import { readFile } from "node:fs/promises";
    export async function readFileJson( fileName ) {
    const text = await readFile( fileName );
    const data = JSON.parse( text );
    return data;
    }
    esm-module-example.js
    

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71. import { readFile } from "node:fs/promises";
    export async function readFileJson( fileName ) {
    const text = await readFile( fileName );
    const data = JSON.parse( text );
    return data;
    }
    esm-module-example.js
    

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72. import { readFile } from "node:fs/promises";
    export async function readFileJson( fileName ) {
    const text = await readFile( fileName );
    const data = JSON.parse( text );
    return data;
    }
    esm-module-example.js
    

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73. esm-module-example.js
    import { readFile } from "node:fs/promises";
    export async function readFileJson( fileName ) {
    const text = await readFile( fileName );
    const data = JSON.parse( text );
    return data;
    }
    esm-example.js
    import { readFileJson } from "./esm-module-example.mjs";
    const baconFile = new URL( "./bacon.json", import.meta.url );
    const bacon = await readFileJson( baconFile );
    console.log( bacon );
    

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74. esm-module-example.js
    import { readFile } from "node:fs/promises";
    export async function readFileJson( fileName ) {
    const text = await readFile( fileName );
    const data = JSON.parse( text );
    return data;
    }
    esm-example.js
    import { readFileJson } from "./esm-module-example.mjs";
    const baconFile = new URL( "./bacon.json", import.meta.url );
    const bacon = await readFileJson( baconFile );
    console.log( bacon );
    

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75. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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76. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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77. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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78. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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79. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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80. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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81. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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82. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    try {
    const pool = await sql.connect( cnx );
    const result = await pool.request()
    .input( "email", sql.VarChar( 100 ), email )
    .query( "select * from accounts where email = @email" );
    return result;
    } catch ( err ) {
    // log error
    }
    }
    sql-example.js
    

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83. const sql = require( "mssql" );
    // Read from environment variables
    const cnx = process.env.SQL_CONNECTION;
    async function getAccountByEmail( email ) {
    ...
    }
    module.exports = {
    getAccountByEmail
    };
    sql-example.js
    

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87. Developer tools
    Package(s) Description
    eslint lint and format rules for JavaScript
    nodemon automatically restarts in dev
    node:test, jest, mocha test frameworks
    testdouble, sinon spies, stubs, mocks
    

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88. Recommended tools
    Package(s) Description
    dotenv loads environment variables from a .env file
    fs-extra adds convenient extensions to file system
    fetch, axios, or got http clients
    socket.io sockets, real-time
    commander command-line argument library for building CLIs
    nexe compile app to a standalone executable
    

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89. Frameworks
    • Express.js
    • Fastify
    • Nest.js
    • Electron.js
    

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90. Integration Strategies
    • Node.js as proxy, use http client
    • nginx
    • Messaging (e.g. RabbitMQ, ZeroMQ Azure
    Service Bus)
    

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91. https://bit.ly/node-crash-course
    

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