private static void importOperations(Onnx.GraphProto onnxGraph, IntermediateGraph intermediateGraph) {
        for (Onnx.ValueInfoProto valueInfo : onnxGraph.getOutputList()) {
            importOperation(valueInfo.getName(), onnxGraph, intermediateGraph);
        }
    }
Converts an ONNX graph to a Vespa IntermediateGraph which is the basis
for generating Vespa ranking expressions.

@author lesters
model-integration/src/main/java/ai/vespa/rankingexpression/importer/onnx/GraphImporter.java