// Test with regex pattern
        execJob.testAddFessCustomSystemProperties(cmdList, "custom\\.prop\\..*");

        assertEquals(2, cmdList.size());
        assertTrue(cmdList.contains("-Dcustom.prop.one=value1"));
        assertTrue(cmdList.contains("-Dcustom.prop.two=value2"));

        // Test with null regex
        cmdList.clear();
        execJob.testAddFessCustomSystemProperties(cmdList, null);