add option type

convert.py

@@ -23,7 +23,7 @@
 from concurrent.futures import ProcessPoolExecutor, ThreadPoolExecutor
 from dataclasses import dataclass
 from pathlib import Path
-from typing import TYPE_CHECKING, Any, Callable, ClassVar, IO, Iterable, Literal, Protocol, TypeVar, runtime_checkable
+from typing import TYPE_CHECKING, Any, Callable, ClassVar, IO, Iterable, Literal, Protocol, TypeVar, runtime_checkable, Optional
 
 import numpy as np
 from sentencepiece import SentencePieceProcessor
@@ -336,6 +336,7 @@ def load(model_plus: ModelPlus) -> Params:
 
         return params
 
+
 @dataclass
 class Metadata:
     name: Optional[str] = None
@@ -370,10 +371,12 @@ def load(metadata_path: Path) -> "Metadata":
 
         return metadata
 
+
 #
 # vocab
 #
 
+
 @runtime_checkable
 class BaseVocab(Protocol):
     tokenizer_model: ClassVar[str]