@Override
    public Reader getRankingExpression(String name) {
        File expressionFile = new File(schemaDir, name);
        try {
            return IOUtils.createReader(expressionFile, "utf-8");
        }
        catch (IOException e) {
            throw new IllegalArgumentException("Could not read ranking expression file '" +
                                               expressionFile.getAbsolutePath() + "'", e);
        }
    }
To avoid either double parsing or supplying a name explicitly
config-model/src/main/java/com/yahoo/config/model/test/MockApplicationPackage.java