Available on macro
Pre-I/O callback.
See also:
https://aantron.github.io/luv/luv/Luv/Prepare
staticinit(loop:Loop):Result<Prepare>
Allocate and initialize a prepare handle.
The handle should be cleaned up with eval.luv.Handle.close when no longer needed.
eval.luv.Handle.close
staticstart(this:Prepare, callback:() ‑> Void):Result<NoData>
Starts the handle with the given callback.
staticstop(this:Prepare):Result<NoData>
Stops the handle.