bw *bufio.Writer // non-nil when data is buffered
}

func http2newBufferedWriter(w io.Writer) *http2bufferedWriter {
	return &http2bufferedWriter{w: w}
}

// bufWriterPoolBufferSize is the size of bufio.Writer's
// buffers created using bufWriterPool.
//
// TODO: pick a less arbitrary value? this is a bit under
// (3 x typical 1500 byte MTU) at least. Other than that,
// not much thought went into it.