layertree/layertree.go
func (p ReplaySnapshotParams) WithFromStep(fromStep int64) *ReplaySnapshotParams {
	p.FromStep = fromStep
	return &p
}
func (p ReplaySnapshotParams) WithFromStep(fromStep int64) *ReplaySnapshotParams {
	p.FromStep = fromStep
	return &p
}
// WithFromStep the first step to replay from (replay from the very start if
// not specified).