private void assertOverride(String input, String cloudName, String expected) {
        assertOverride(input, Environment.defaultEnvironment(), RegionName.defaultName(), CloudName.from(cloudName), 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