public static String getProperty(final String propertyName)
    {
        final String propertyValue = System.getProperty(propertyName);

        return NULL_PROPERTY_VALUE.equals(propertyValue) ? null : propertyValue;
    }
@Test
    void shouldGetDefaultProperty()
    {
        final String key = "org.agrona.test.case";
        final String defaultValue = "default";

        assertEquals(defaultValue, SystemUtil.getProperty(key, defaultValue));
    }