What is logged, and why? The snippet inspects `readableFlowing` at three points on a fresh Readable.

const { Readable } = require('stream'); const r = Readable.from(['x']); console.log(r.readableFlowing); // A r.on('data', () => {}); console.log(r.readableFlowing); // B r.pause(); console.log(r.readableFlowing); // C