text: from google.protobuf.message import (
      Message,
  )
  from typing import (
      Optional,
      Text,
  )
  
  
  class SourceContext(Message):
      file_name = ...  # type: Text
  
      def __init__(self,
                   file_name: Optional[Text] = ...,
                   ) -> None: ...
  
      @classmethod
      def FromString(cls, s: str) -> SourceContext: ...
  