code: func ValidateDaemonSetUpdate(ds, oldDS *apps.DaemonSet) field.ErrorList {
  	allErrs := apivalidation.ValidateObjectMetaUpdate(&ds.ObjectMeta, &oldDS.ObjectMeta, field.NewPath("metadata"))
  	allErrs = append(allErrs, ValidateDaemonSetSpecUpdate(&ds.Spec, &oldDS.Spec, field.NewPath("spec"))...)
  	allErrs = append(allErrs, ValidateDaemonSetSpec(&ds.Spec, field.NewPath("spec"))...)
  	return allErrs
  }
docs: // ValidateDaemonSetUpdate tests if required fields in the DaemonSet are set.