Execution sequence of node stream.Writable during destroy

writable-stream-destroy.js

const hello = new require('stream').Writable({
  destroy (err, callback) {
    console.log('2 before callback in _destroy')
    callback(err)
    console.log('3 after callback in _destory')
  }
}).on('error', err => console.log('6 error'))
  .on('close', () => console.log('7 close'))

console.log('1 before destroy')
process.nextTick(() => console.log('5 before destroy nextTicked'))
hello.destroy(new Error('some error'))
console.log('4 after destroy')
process.nextTick(() => console.log('8 after destroy nextTicked'))

/**
 * ```
 * $ node test.js
 * 1 before destroy
 * 2 before callback in _destroy
 * 3 after callback in _destory
 * 4 after destroy
 * 5 before destroy nextTicked
 * 6 error
 * 7 close
 * 8 after destroy nextTicked
 * ```
 *
 * The output shows that:
 * 1. the internal _destroy is triggered synchronously with destroy.
 * 2. error and close are emitted via nextTick.
 */