code: def test_is_whitespace(self):
      self.assertTrue(_is_whitespace(" "))
      self.assertTrue(_is_whitespace("\t"))
      self.assertTrue(_is_whitespace("\r"))
      self.assertTrue(_is_whitespace("\n"))
      self.assertTrue(_is_whitespace("\u00A0"))
  
      self.assertFalse(_is_whitespace("A"))
      self.assertFalse(_is_whitespace("-"))
  
file_path: texar/tests/data/tokenizers/bert_tokenizer_utils_test.py
imports: import tensorflow
  from texar.tf.data.tokenizers.bert_tokenizer_utils import BasicTokenizer, WordpieceTokenizer, _is_control, _is_punctuation, _is_whitespace
label_desc: Use image node_id 5 for calling the BERTTokenizerUtilsTest obj's underlying member method code with example usage: obj.test_is_whitespace() without return types