code: def test_empty_word_small_tok(self):
      tok = BlenderbotSmallTokenizer.from_pretrained(
          "facebook/blenderbot-90M"
      )
      src_text = "I am a small frog ."
      src_text_dot = "."
      encoded = tok(src_text)["input_ids"]
      encoded_dot = tok(src_text_dot)["input_ids"]
  
      assert encoded[-1] == encoded_dot[0]
  
file_path: transformers/tests/models/blenderbot_small/test_tokenization_blenderbot_small.py
imports: import json
  import os
  import unittest
  from transformers.models.blenderbot_small.tokenization_blenderbot_small import VOCAB_FILES_NAMES, BlenderbotSmallTokenizer
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 6 for calling the BlenderbotSmallTokenizerTest obj's underlying member method code with example usage: obj.test_empty_word_small_tok() without return types