code: func ValidateRuntimeClassName(name string, fldPath *field.Path) field.ErrorList {
  	var allErrs field.ErrorList
  	for _, msg := range apimachineryvalidation.NameIsDNSSubdomain(name, false) {
  		allErrs = append(allErrs, field.Invalid(fldPath, name, msg))
  	}
  	return allErrs
  }
docs: // ValidateRuntimeClassName can be used to check whether the given RuntimeClass name is valid.
  // Prefix indicates this name will be used as part of generation, in which case
  // trailing dashes are allowed.