在Java 9中如何显示当前线程的所有堆栈帧？

import java.lang.StackWalker.StackFrame;
import java.lang.reflect.Method;
import java.util.List;
import java.util.stream.Collectors;

public class StackWalkerTest {
   public static void main(String args[]) throws Exception {
      Method test1Method = Helper1.class.<strong>getDeclaredMethod</strong>("test1", (Class<!--?-->[])null);
      test1Method.invoke(null, (Object[]) null);
   }
}

<strong>// Helper1 class
</strong>class Helper1 {
   protected static void test1() {
      Helper2.test2();
   }
}

<strong>// Helper2 class</strong>
class Helper2 {
   protected static void test2() {
      <strong>List<StackFrame></strong> stack = <strong>StackWalker.getInstance().walk</strong>((s) -> s.<strong>collect</strong>(Collectors.toList()));
      for(<strong>StackFrame </strong>frame : stack) {
         System.out.println(frame.<strong>getClassName()</strong> + " " + frame.<strong>getLineNumber()</strong> + " " +    frame.<strong>getMethodName()</strong>);
      }
   }
}

<strong>Helper2 23 test2
Helper1 16 test1
StackWalkerTest 9 main</strong>