code: def test_is_control(self):
      self.assertTrue(_is_control("\u0005"))
  
      self.assertFalse(_is_control("A"))
      self.assertFalse(_is_control(" "))
      self.assertFalse(_is_control("\t"))
      self.assertFalse(_is_control("\r"))
  
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 6 for calling the BERTTokenizerUtilsTest obj's underlying member method code with example usage: obj.test_is_control() without return types