code: def test_splits_roberta(self):
      tokenizer = PretrainedTransformerTokenizer("roberta-base")
  
      sentence = "A, <mask> AllenNLP sentence."
      expected_tokens = [
          "<s>",
          "A",
          ",",
          "<mask>",
          "ĠAllen",
          "N",
          "LP",
          "Ġsentence",
          ".",
          "</s>",
      ]
      tokens = [t.text for t in tokenizer.tokenize(sentence)]
      assert tokens == expected_tokens
  
imports: from typing import Iterable, List
  import pytest
  from allennlp.common import Params
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data import Token
  from allennlp.data.tokenizers import PretrainedTransformerTokenizer
label_desc: Use image node_id 1 for calling the TestPretrainedTransformerTokenizer obj's underlying member method code with example usage: obj.test_splits_roberta() without return types