Overwrite get_clean_sequence as this was causing a bottleneck (#13183)

tests/test_tokenization_luke.py

@@ -15,6 +15,7 @@
 
 
 import unittest
+from typing import Tuple
 
 from transformers import AddedToken, LukeTokenizer
 from transformers.testing_utils import require_torch, slow
@@ -81,6 +82,11 @@ class Luke(TokenizerTesterMixin, unittest.TestCase):
         assert encoded_sentence == encoded_text_from_decode
         assert encoded_pair == encoded_pair_from_decode
 
+    def get_clean_sequence(self, tokenizer, max_length=20) -> Tuple[str, list]:
+        txt = "Beyonce lives in Los Angeles"
+        ids = tokenizer.encode(txt, add_special_tokens=False)
+        return txt, ids
+
     def test_space_encoding(self):
         tokenizer = self.get_tokenizer()