func treeFunc(b *Brain, used, missing *dep.Set) func(string) ([]*dep.KeyPair, error) {
	return func(s string) ([]*dep.KeyPair, error) {
		result := []*dep.KeyPair{}

		if len(s) == 0 {
			return result, nil
		}

		d, err := dep.NewKVListQuery(s)
		if err != nil {
			return result, err
		}

		used.Add(d)

		// Only return non-empty top-level keys
		if value, ok := b.Recall(d); ok {
			for _, pair := range value.([]*dep.KeyPair) {
				parts := strings.Split(pair.Key, "/")
				if parts[len(parts)-1] != "" {
					result = append(result, pair)
				}
			}
			return result, nil
		}

		missing.Add(d)

		return result, nil
	}
}
func treeFunc(b *Brain, used, missing *dep.Set) func(string) ([]*dep.KeyPair, error) {
	return func(s string) ([]*dep.KeyPair, error) {
		result := []*dep.KeyPair{}

		if len(s) == 0 {
			return result, nil
		}

		d, err := dep.NewKVListQuery(s)
		if err != nil {
			return result, err
		}

		used.Add(d)

		// Only return non-empty top-level keys
		if value, ok := b.Recall(d); ok {
			for _, pair := range value.([]*dep.KeyPair) {
				parts := strings.Split(pair.Key, "/")
				if parts[len(parts)-1] != "" {
					result = append(result, pair)
				}
			}
			return result, nil
		}

		missing.Add(d)

		return result, nil
	}
}
// treeFunc returns or accumulates keyPrefix dependencies.