Forums - Why ssd-mobilenet has only one output node?

Hi,everyone

   I invoke ssd-mobilenet model in my own android project,the model has been convert to dlc by the following script:

SNPE.NeuralNetworkBuilder builder = null;
    try {
      File modelDir = mApplication.getApplicationContext().getExternalFilesDir("models");
      File file = new File(modelDir, modelName);

      builder = new SNPE.NeuralNetworkBuilder(mApplication)
              .setDebugEnabled(false)
              .setRuntimeOrder(NeuralNetwork.Runtime.DSP)
              .setModel(file)
              .setCpuFallbackEnabled(true)
              .setUseUserSuppliedBuffers(true);
    } catch (IllegalStateException e) {
      Log.e("SNPE", e.getMessage(), e);
    } catch (IOException e) {
      e.printStackTrace();
    }

    NeuralNetwork mNeuralNetwork = builder.build();

    final String inputLayer = mNeuralNetwork.getInputTensorsNames().iterator().next();

final FloatTensor tensor = mNeuralNetwork.createFloatTensor(
        mNeuralNetwork.getInputTensorsShapes().get(inputLayer));
float[] input = loadRgbBitmapAsFloat(bitmap);
final Map<String, FloatTensor> inputs = new HashMap<>();
tensor.write(input, 0, input.length);
inputs.put(inputLayer, tensor);

mNeuralNetwork.execute(inputs);

It really works.However,I found that the result after execute has only one node:detection_classes:0,no detection_boxes and detection_scores.

I wonder why and how should I get the correct result? Thanks