page/page.go
func (p StartScreencastParams) WithEveryNthFrame(everyNthFrame int64) *StartScreencastParams {
	p.EveryNthFrame = everyNthFrame
	return &p
}
func (p StartScreencastParams) WithEveryNthFrame(everyNthFrame int64) *StartScreencastParams {
	p.EveryNthFrame = everyNthFrame
	return &p
}
// WithEveryNthFrame send every n-th frame.