arthas/tutorials/katacoda/arthas-basics-en/thread.md

The thread 1{{execute interrupt}} command prints the stack of thread ID 1.

Arthas supports pipes, and you can find main class with thread 1 | grep 'main('{{execute T2}}.

You can see that main class is demo.MathGame:

$ thread 1 | grep 'main('
    at demo.MathGame.main(MathGame.java:17)