Fix import bug

Author: LakshyAAAgrawal

src/monitors4codegen/monitor_guided_decoding/hf_gen.py

@@ -8,6 +8,7 @@
 from asyncio.events import AbstractEventLoop
 from typing import List, Union
 from transformers import LogitsProcessor
+from monitors4codegen.monitor_guided_decoding.monitor import Monitor
 
 class MGDLogitsProcessor(LogitsProcessor):
     """