code: def test_sequence_classifier_export_to_onnx(self):
      for num_layers in [1, 2, 4]:
          classifier_export(
              SequenceClassifier(
                  hidden_size=256, num_classes=16, num_layers=num_layers
              )
          )
  
imports: import os
  import tempfile
  import onnx
  import pytest
  import pytorch_lightning
  import torch
  import wget
  from omegaconf import DictConfig, OmegaConf
  from nemo.collections import nlp
  from nemo.collections.nlp.models import IntentSlotClassificationModel
  from nemo.collections.nlp.modules.common import SequenceClassifier, SequenceRegression, SequenceTokenClassifier, TokenClassifier
label_desc: Use image node_id 4 for calling the TestExportableClassifiers obj's underlying member method code with example usage: obj.test_sequence_classifier_export_to_onnx() without return types