static Tensor miTensor() {
        return Tensor.from("tensor<bfloat16>(x{},y[2]):{a:[1,2], b:[3,4]}");
    }
Functional testing of {@link JsonRenderer}.

@author Steinar Knutsen
@author bratseth
container-search/src/test/java/com/yahoo/search/rendering/JsonRendererTestCase.java