class Async::HTTP::Protocol::HTTP2::Stream

While the input stream is relatively straight forward, the output stream can trigger the second case above
- A frame is sent which causes this stream to enter the closed state. This method will be invoked from that task.
- A frame is received which causes this stream to enter the closed state. This method will be invoked from the background reader task.
When the stream transitions to the closed state, this method is called. There are roughly two ways this can happen:

def closed(error)
	super
	
	if @input
		@input.close(error)
		@input = nil
	end
	
	if @output
		@output.stop(error)
		@output = nil
	end
	
	return self
end