String asString(Optional<OrderedTensorType> type) {
        return type.map(OrderedTensorType::toString).orElse("(unknown)");
    }
Returns the largest value type among the input value types.
This should only be called after it has been verified that input types are available.

@throws IllegalArgumentException if a type cannot be uniquely determined
@throws RuntimeException if called when input types are not available
model-integration/src/main/java/ai/vespa/rankingexpression/importer/operations/IntermediateOperation.java