@Override
    public Double getAsDouble(TensorAddress address) {
        try {
            long index = toValueIndex(address, dimensionSizes, type);
            if (index < 0 || size() <= index) return null;
            return get(index);
        } catch (IllegalArgumentException e) {
            return null;
        }
    }
Returns the value at this address, or 0.0 if there is no value at this address
vespajlib/src/main/java/com/yahoo/tensor/IndexedTensor.java