assertNotSame(instance1, instance2);
        // Getting instance again should return the same as instance2
        assertSame(instance2, LogStream.getInstance());
    }

    @Test
    void testNullStreamHandling() {
        // Test that passing null to setInstance throws NullPointerException
        // This is expected behavior as PrintStream doesn't accept null
        assertThrows(NullPointerException.class, () -> {