compareMeta1 := make(map[string]string)
	for k, v := range oi1.UserDefined {
		var found bool
		for _, prefix := range compareKeys {
			if !stringsHasPrefixFold(k, prefix) {
				continue
			}
			found = true
			break
		}
		if found {
			compareMeta1[strings.ToLower(k)] = v
		}
	}

	compareMeta2 := make(map[string]string)

// To signify no more results are on an input channel, close it.
// The output channel will be closed when all inputs are emptied.
// If file names are equal, compareMeta is called to select which one to choose.
// The entry not chosen will be discarded.
// If the context is canceled the function will return the error,
// otherwise the function will return nil.