private void assertOverride(Environment environment, RegionName region, String expected) throws TransformerException {
        assertOverride(input, environment, region, expected);
    }
Tests that searchers referred to with idref are overridden per cloud
and that searchers not referred to with idref are not overridden.
config-application-package/src/test/java/com/yahoo/config/application/OverrideProcessorTest.java