code: def example_train_sample(self):
      edge_index = torch.tensor(
          [[0, 1, 1, 2], [1, 0, 2, 1]], dtype=torch.long
      )
      x = torch.tensor([[-1], [0], [1]], dtype=torch.float)
      return {
          DataKeys.INPUT: Data(x=x, edge_index=edge_index),
          DataKeys.TARGET: 1,
      }
  
file_path: lightning-flash/tests/graph/classification/test_model.py
imports: from typing import Any
  import pytest
  import torch
  from flash import RunningStage, Trainer
  from flash.core.data.data_module import DataModule
  from flash.core.data.io.input import DataKeys
  from flash.core.utilities.imports import _TOPIC_GRAPH_AVAILABLE
  from flash.graph.classification import GraphClassifier
  from flash.graph.classification.input import GraphClassificationDatasetInput
  from flash.graph.classification.input_transform import GraphClassificationInputTransform
  from torch import Tensor
  from tests.helpers.task_tester import TaskTester
label_desc: Use image node_id 3 for calling the TestGraphClassifier obj's underlying member method code with example usage: obj.example_train_sample() and returns: dict