code: func ValidateConfiguration(config *resourcequotaapi.Configuration) field.ErrorList {
  	allErrs := field.ErrorList{}
  	fldPath := field.NewPath("limitedResources")
  	for i, limitedResource := range config.LimitedResources {
  		idxPath := fldPath.Index(i)
  		if len(limitedResource.Resource) == 0 {
  			allErrs = append(allErrs, field.Required(idxPath.Child("resource"), ""))
  		}
  	}
  	return allErrs
  }
docs: // ValidateConfiguration validates the configuration.