code: func validateConfigMapNodeConfigSourceSpec(source *core.ConfigMapNodeConfigSource, fldPath *field.Path) field.ErrorList {
  	allErrs := field.ErrorList{}
  	// uid and resourceVersion must not be set in spec
  	if string(source.UID) != "" {
  		allErrs = append(allErrs, field.Forbidden(fldPath.Child("uid"), "uid must not be set in spec"))
  	}
  	if source.ResourceVersion != "" {
  		allErrs = append(allErrs, field.Forbidden(fldPath.Child("resourceVersion"), "resourceVersion must not be set in spec"))
  	}
  	return append(allErrs, validateConfigMapNodeConfigSource(source, fldPath)...)
  }
docs: // validation specific to Node.Spec.ConfigSource.ConfigMap