Annotate some functions that return None

Summary: Test functions return None. This codemod fixes that so type annotation efforts can focus on trickier cases.

Reviewed By: azad-meta

Differential Revision: D52570419

fbshipit-source-id: f99c81915d3d7a5b7b806b59cffb9eb2c72be88d

Author: r-barnes

test/torchtext_unittest/test_transforms.py

@@ -709,7 +709,7 @@ def test_gpt2_bpe_tokenizer(self, test_scripting, return_tokens):
         """test tokenization on single sentence input as well as batch on sentences"""
         self._gpt2_bpe_tokenizer(self._load_tokenizer(test_scripting=test_scripting, return_tokens=return_tokens))
 
-    def test_gpt2_bpe_decoder(self):
+    def test_gpt2_bpe_decoder(self) -> None:
         """test string output returned by decoder given the token ids"""
         self._gpt2_bpe_decoder(self._load_tokenizer(test_scripting=False, return_tokens=False))
         self._gpt2_bpe_decoder_with_special_tokens(self._load_tokenizer(test_scripting=False, return_tokens=False))