fix typedef

Author: mr-c

cwltool/draft2tool.py

@@ -14,7 +14,7 @@
 import shellescape
 from schema_salad.ref_resolver import file_uri, uri_file_path
 from schema_salad.sourceline import SourceLine, indent
-from typing import Any, Callable, cast, Generator, Text, Union, Dict
+from typing import Any, Callable, cast, Generator, Optional, Text, Union, Dict
 
 from .builder import CONTENT_LIMIT, substitute, Builder
 from .pathmapper import adjustFileObjs, adjustDirObjs, visit_class
@@ -172,7 +172,7 @@ def __init__(self, toolpath_object, **kwargs):
         # type: (Dict[Text, Any], **Any) -> None
         super(CommandLineTool, self).__init__(toolpath_object, **kwargs)
 
-    def makeJobRunner(self, use_container=True):  # type: () -> JobBase
+    def makeJobRunner(self, use_container=True):  # type: (Optional[bool]) -> JobBase
         dockerReq, _ = self.get_requirement("DockerRequirement")
         if dockerReq and use_container:
             return DockerCommandLineJob()