id := f.Setting(i).ID
		if seen[id] {
			return true
		}
		seen[id] = true
	}
	return false
}

// ForeachSetting runs fn for each setting.
// It stops and returns the first error.
func (f *http2SettingsFrame) ForeachSetting(fn func(http2Setting) error) error {
	f.checkValid()
	for i := 0; i < f.NumSettings(); i++ {
		if err := fn(f.Setting(i)); err != nil {
			return err