@Override
    public CompositeNode setChildren(List<ExpressionNode> children) {
        List<TensorFunction<Reference>> wrappedChildren = children.stream()
                                                                 .map(ExpressionTensorFunction::new)
                                                                 .collect(Collectors.toList());
        return new TensorFunctionNode(function.withArguments(wrappedChildren));
    }
Returns the tensor function wrapped by this
searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/TensorFunctionNode.java