code: func NewSecondaryLayer(cmp SecondaryCmpFunc) SecondaryLayer {
  	var synced uint64
  	return SecondaryLayer{
  		synced: &synced,
  		store:  NewSecondaryTree(cmp),
  		offset: uint64(util.RevOffset()),
  		lock:   lockie.NewLockie(),
  		cmp:    cmp,
  	}
  }
docs: // NewSecondaryLayer initializes a new secondary layer handle.