module Async::IO::Peer

def connected?

May return false positive, but won't return false negative.
Is it likely that the socket is still connected? 
def connected?
	return false if @io.closed?
	
	# If we can wait for the socket to become readable, we know that the socket may still be open.
	result = to_io.recv_nonblock(1, Socket::MSG_PEEK, exception: false)
	
	# Either there was some data available, or we can wait to see if there is data avaialble.
	return !result.empty? || result == :wait_readable
end