class Async::Scheduler

@parameter duration [Numeric | Nil] The time in seconds to sleep, or if nil, indefinitely.

@asynchronous May be non-blocking.
@public Since *Async v2* and *Ruby v3.1*.

Sleep for the specified duration.

def kernel_sleep(duration = nil)
	# Fiber.blocking{$stderr.puts "kernel_sleep(#{duration}, #{Fiber.current})"}
	
	if duration
		self.block(nil, duration)
	else
		self.transfer
	end
end