func FetchRedHatFiles(versions []string) ([]FetchResult, error) {
	reqs := newRedHatFetchRequests(versions)
	if len(reqs) == 0 {
		return nil,
			fmt.Errorf("There are no versions to fetch")
	}
	results, err := fetchFeedFiles(reqs)
	if err != nil {
		return nil,
			xerrors.Errorf("Failed to fetch. err: %w", err)
	}
	return results, nil
}
FetchRedHatFiles fetch OVAL from RedHat
package fetcher
import (
	"fmt"
	"golang.org/x/xerrors"
)
func newRedHatFetchRequests(target []string) (reqs []fetchRequest) {
	const t = "https://www.redhat.com/security/data/oval/com.redhat.rhsa-RHEL%s.xml.bz2"
	for _, v := range target {
		reqs = append(reqs, fetchRequest{
			target:       v,
			url:          fmt.Sprintf(t, v),
			bzip2:        true,
			concurrently: false,
		})
	}
	return
}