private Collection<ProcessorFactory> rankProfileProcessors() {
        return List.of(
                RankProfileTypeSettingsProcessor::new,
                ReservedFunctionNames::new,
                RankingExpressionTypeResolver::new);
    }
Processors of rank profiles only (those who tolerate and do something useful when the search field is null)
config-model/src/main/java/com/yahoo/schema/processing/Processing.java