code: func (p *NS1Provider) ApplyChanges(changes *plan.Changes) error {
  	combinedChanges := make([]*ns1Change, 0, len(changes.Create)+len(changes.UpdateNew)+len(changes.Delete))
  
  	combinedChanges = append(combinedChanges, newNS1Changes(ns1Create, changes.Create)...)
  	combinedChanges = append(combinedChanges, newNS1Changes(ns1Update, changes.UpdateNew)...)
  	combinedChanges = append(combinedChanges, newNS1Changes(ns1Delete, changes.Delete)...)
  
  	return p.ns1SubmitChanges(combinedChanges)
  }
docs: // ApplyChanges applies a given set of changes in a given zone.