No matter if stash succed or not unstash always pass.
I want to stash file but I dont know if it exists. If file exists everything goes well my_jar is saved and I can unstash it. But... if file doesnt exists it goes to catch() section and I guess that unstash also should go to catch() section but it's not happening. Instead of it unstash return success (without any files). It means that during stash section "my_jar" label is created and unstash recognize it as stashed file.