@Test
    void testDirectlyManagedIterator() {
        try (Handle h = h2Extension.openHandle()) {
            try (ResultIterator<String> it = h.createQuery("SELECT name from users")
                    .mapTo(String.class)
                    .iterator()) {
                assertThat(it).hasNext();
                assertThat(it.next()).isNotNull();
            }
        }
    }
Many tests that try to provoke leaks and see whether the various checkers find them and various cleanup strategies catch them.
core/src/test/java/org/jdbi/v3/core/statement/LeakTest.java