DerivedConfiguration derive(String dirName, ApplicationBuilder builder, Schema schema) throws IOException {
        DerivedConfiguration config = new DerivedConfiguration(schema,
                                                               builder.getRankProfileRegistry(),
                                                               builder.getQueryProfileRegistry());
        return export(dirName, builder, config);
    }
Superclass of tests needing file comparisons

@author bratseth
config-model/src/test/java/com/yahoo/schema/derived/AbstractExportingTestCase.java