Fixed some style validations on chatbot.py

chatbot.py

@@ -17,7 +17,8 @@ prompt.
 import argparse
 import torch
 
-from transformers import AutoModelForCausalLM, AutoTokenizer, PreTrainedModel, PreTrainedTokenizerBase
+from transformers import AutoModelForCausalLM, AutoTokenizer, PreTrainedModel,\
+    PreTrainedTokenizerBase
 from typing import Optional, Union
 
 
@@ -87,7 +88,7 @@ class ChatBot:
         self.human_identifier = human_identifier
         self.bot_identifier = bot_identifier
 
-    def chat(self, input_text):
+    def chat(self, input_text: str) -> str:
         """
         Generates a response from the prompt (and optionally the context) where
         it adds the `input_text` as if it was part of the HUMAN dialog