code: def __init__(self) -> None:
      super().__init__()
      self.model = torch.nn.Sequential(
          torch.nn.Conv2d(
              in_channels=1,
              out_channels=16,
              kernel_size=5,
              stride=1,
              padding=2,
          ),
          torch.nn.ReLU(),
          torch.nn.MaxPool2d(kernel_size=2),
          torch.nn.Conv2d(16, 32, 5, 1, 2),
          torch.nn.ReLU(),
          torch.nn.MaxPool2d(2),
          torch.nn.Flatten(),
          # fully connected layer, output 10 classes
          torch.nn.Linear(32 * 7 * 7, 10),
      )
      self.loss_fn = torch.nn.CrossEntropyLoss()
  
file_path: pytorch-lightning/examples/fabric/build_your_own_trainer/run.py
imports: import lightning
  import torch
  from torchmetrics.functional.classification.accuracy import accuracy
  from trainer import MyCustomTrainer
label_desc: Use image node_id 1 to create a new MNISTModule object from inherited base class: L with example: obj = MNISTModule()