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chmod
Forget the chmod octals (the numbers). Set permission the easy way using the keywords

// know the ownerships:
u = User (you)
g = Group
o = Other (aka. 'World')
a = All of the above

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const Web3 = require('web3') // Web3 0.20.4 or web3 1 beta
const truffleContract = require("truffle-contract")
const contractArtifact = require('./build/contracts/TutorialToken.json')

const providerUrl = 'http://localhost:8545'
const provider = new Web3.providers.HttpProvider(providerUrl)

const contract = truffleContract(contractArtifact)
contract.setProvider(provider)

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Concurrency in JavaScript

Javascript is a programming language with a peculiar twist. Its event driven model means that nothing blocks and everything runs concurrently. This is not to be confused with the same type of concurrency as running in parallel on multiple cores. Javascript is single threaded so each program runs on a single core yet every line of code executes without waiting for anything to return. This sounds weird but it's true. If you want to have any type of sequential ordering you can use events, callbacks, or as of late promises.

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class MyClass {
  static final MyClass _singleton = new MyClass._internal();

  factory MyClass() {
    return _singleton;
  }

  MyClass._internal() {
    ... // initialization logic here
  }