code: def test_argmax_prediction_processor(self):
      processor = ArgMaxPredictionProcessor(config={})
      batch = SampleList(
          {"id": torch.tensor([1, 2, 3, 4, 5], dtype=torch.long)}
      )
      model_output = {"scores": torch.rand(5, 4)}
      report = Report(batch, model_output)
  
      predictions = processor(report)
  
      expected_answers = [1, 1, 2, 1, 3]
      expected = []
      for idx, answer in enumerate(expected_answers):
          expected.append({"id": idx + 1, "answer": answer})
  
      self.assertEqual(predictions, expected)
  
file_path: mmf/tests/datasets/test_prediction_processors.py
imports: import unittest
  import torch
  from mmf.common.report import Report
  from mmf.common.sample import SampleList
  from mmf.datasets.processors.prediction_processors import ArgMaxPredictionProcessor
label_desc: Use image node_id 2 for calling the TestDatasetProcessors obj's underlying member method code with example usage: obj.test_argmax_prediction_processor() without return types