private static void decodeBlock(Inspector block, MixedTensor.BoundBuilder mixedBuilder) {
        if (block.type() != Type.OBJECT)
            throw new IllegalArgumentException("Expected an item in a blocks array to be an object, not " + block.type());
        mixedBuilder.block(decodeAddress(block.field("address"), mixedBuilder.type().mappedSubtype()),
                           decodeValuesInBlock(block.field("values"), mixedBuilder));
    }
Deserializes the given tensor from JSON format
vespajlib/src/main/java/com/yahoo/tensor/serialization/JsonFormat.java