@Override
    protected void onDeserialize(Deserializer buf) {
        super.onDeserialize(buf);
        count = buf.getLong(null);
        sum = buf.getDouble(null);
        sumOfSquared = buf.getDouble(null);
    }
Constructor used for deserialization. Will be instantiated with a default sketch.
searchlib/src/main/java/com/yahoo/searchlib/aggregation/StandardDeviationAggregationResult.java