A `Writable` has `highWaterMark: 16384` (16 KB). A producer writes a single 64 KB chunk in one `write()` call. Internally, what does `writableLength` become, what does `write()` return, and is the oversized chunk rejected?
const { Writable } = require('stream');
const w = new Writable({ highWaterMark: 16384, write(c, e, cb) { /* slow */ } });
const ok = w.write(Buffer.alloc(65536));