Work in Progress

Good read. Thanks! I'm gonna give this to `nextTick` to make it consistent with the other branch above it.

Something related: I'm not sure if you guys noticed this before, but I gave it another look and found out `Writable` actually has the sync/async check mentioned in that blog post. Check [0] and [1]. 

[0] https://github.com/virgo-agent-toolkit/luvit-stream/blob/6cb169c41325637fad30f9090beb6b68f833510d/lib/stream_writable.lua#L310
[1] https://github.com/virgo-agent-toolkit/luvit-stream/blob/6cb169c41325637fad30f9090beb6b68f833510d/lib/stream_writable.lua#L363