private void bindStreamingFeatures(Map<String, Double> featureItem, Context context) {
        for (Map.Entry<String, Double> feature : featureItem.entrySet())
            context.put(feature.getKey(), feature.getValue());
    }
Read an ad-hoc file format with some similarly ad hoc code
searchlib/src/test/java/com/yahoo/searchlib/rankingexpression/evaluation/StreamEvaluationBenchmark.java