// be larger than 2^32-1. If the value is zero or larger than the
	// maximum, a default value will be used instead.
	MaxUploadBufferPerStream int32

	// NewWriteScheduler constructs a write scheduler for a connection.
	// If nil, a default scheduler is chosen.
	NewWriteScheduler func() http2WriteScheduler

	// CountError, if non-nil, is called on HTTP/2 server errors.
	// It's intended to increment a metric for monitoring, such