assertThrows(PotentialDeadlockException.class, () -> lockA.lock());
    checkMessage(expected, "LockC -> LockA", "LockB -> LockC", "LockA -> LockB");
  }

  public void testReentrancy_noDeadlock() {
    lockA.lock();
    lockB.lock();
    lockA.lock(); // Should not assert on lockB -> reentrant(lockA)
  }

  public void testExplicitOrdering_noViolations() {
    lock1.lock();