@Override
    public TensorType getType(Reference reference) {
        Integer index = nameToIndex().get(reference.toString());
        if (index == null) return null;
        return values[index].type();
    }
Puts a value by index.
The value will be frozen if it isn't already.
searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/evaluation/ArrayContext.java