input: Write a python function to create an instance of the MNISTClassifier class and check if its output shape is as expected.
  ```python
  import torch
  
  def test_mnist_classifier():
      model = MNISTClassifier()
      input_tensor = torch.randn(1, 1, 28, 28)
      output = model(input_tensor)
      assert output.shape == (1, 10), f"Expected shape (1, 10), but got {output.shape}"
  
  test_mnist_classifier()
output: def test_mnist_classifier():
      model = MNISTClassifier()
      input_tensor = torch.randn(1, 1, 28, 28)
      output = model(input_tensor)
      assert output.shape == (1, 10), f"Expected shape (1, 10), but got {output.shape}"
  
  test_mnist_classifier()