if err != nil {
		log.Fatalf("unexpected api file: %v", name)
	}
	return n >= 19 // started tracking approvals in Go 1.19
}

func (w *Walker) collectDeprecated() {
	isDeprecated := func(doc *ast.CommentGroup) bool {
		if doc != nil {
			for _, c := range doc.List {
				if strings.HasPrefix(c.Text, "// Deprecated:") {
					return true
				}
			}
		}
		return false
	}