from threading import Thread

class A:
	def not_see(self, *args):
		# Checking inputs only
		
		assert False, "Last traceback entry shouldn't be seen"
	
	def see(self, *args):
		# Do something weird
		
		assert False, "Last traceback entry must be seen"

a = A()
Thread(target=a.see, name="'Ought to be seen'").start()
Thread(target=a.not_see, name="'Not to be seen'").start()