chain.changePasswordResult = true;

        boolean result = chain.changePassword("testuser", "newpassword123");

        assertTrue(result);
        assertEquals(1, chain.changePasswordCalls.size());
        assertEquals("testuser", chain.changePasswordCalls.get(0).getKey());
        assertEquals("newpassword123", chain.changePasswordCalls.get(0).getValue());
    }

    // Test changePassword with failure
    @Test