code: def __init__(self, num_classes: int):
      self.num_classes = num_classes
  
imports: from typing import Any
  from unittest.mock import patch
  import pytest
  import torch
  from flash import Trainer
  from flash.core.data.io.input import DataKeys
  from flash.core.utilities.imports import _TOPIC_IMAGE_AVAILABLE, _TOPIC_SERVE_AVAILABLE
  from flash.image import ImageClassifier
  from torch import Tensor
  from tests.helpers.task_tester import TaskTester
label_desc: Use image node_id 1 to create a new DummyMultiLabelDataset object from inherited base classes: torch.utils.data with example: obj = DummyMultiLabelDataset(num_classes)