code: def test_get_normalized_tokens():
      sentence = "I am happy"
      tokens = ["i", "am", "happy"]
      assert tokens == QAMetrics._get_normalized_tokens(sentence)
  
      sentence = "I am a person"
      tokens = ["i", "am", "person"]
      assert tokens == QAMetrics._get_normalized_tokens(sentence)
  
      sentence = "I am a person."
      tokens = ["i", "am", "person"]
      assert tokens == QAMetrics._get_normalized_tokens(sentence)
  
file_path: NeMo/tests/collections/nlp/test_qna.py
imports: import collections
  import pytest
  import torch
  from nemo.collections.nlp.data.question_answering.dataset.qa_dataset import QADataset
  from nemo.collections.nlp.data.question_answering.dataset.qa_gpt_dataset import GPTQADataset
  from nemo.collections.nlp.metrics.qa_metrics import QAMetrics
label_desc: Use image node_id 4 for calling a global function with example usage: test_get_normalized_tokens() without return types