private RankingExpression assertEvaluates(String expectedTensor, String expressionString, String ... tensorArguments) {
        MapContext context = new MapContext();
        int argumentIndex = 0;
        for (String tensorArgument : tensorArguments)
            context.put("tensor" + (argumentIndex++), new TensorValue(Tensor.from(tensorArgument)));
        return assertEvaluates(new TensorValue(Tensor.from(expectedTensor)), expressionString, context);
    }
"XOR" neural network, separate expression per layer
searchlib/src/test/java/com/yahoo/searchlib/rankingexpression/evaluation/NeuralNetEvaluationTestCase.java