code: def test_single_input(self):
      model = SingleInputNet()
      input = (1, 28, 28)
      result, (total_params, trainable_params) = summary_string(
          model, input, device="cpu"
      )
      self.assertEqual(type(result), str)
      self.assertEqual(total_params, 21840)
      self.assertEqual(trainable_params, 21840)
  
file_path: pytorch-summary/torchsummary/tests/unit_tests/torchsummary_test.py
imports: import unittest
  from torchsummary import summary, summary_string
  from torchsummary.tests.test_models.test_model import SingleInputNet, MultipleInputNet, MultipleInputNetDifferentDtypes
  import torch
label_desc: Use image node_id 1 for calling the torchsummarystringTests obj's underlying member method code with example usage: obj.test_single_input() without return types