text: import os
  from pathlib import Path
  from typing import Union
  
  
  class FileIO:
      def __init__(self, path: Union[os.PathLike, str]):
          if isinstance(path, str):
              path = Path(path)
          self.path = path
  
      def read(self):  # Returns bytes/str
          # We would like to read unicode here, but we cannot, because we are not
          # sure if it is a valid unicode file. Therefore just read whatever is
          # here.
          with open(self.path, 'rb') as f:
              return f.read()
  
      def get_last_modified(self):
          """
          Returns float - timestamp or None, if path doesn't exist.
          """
          try:
              return os.path.getmtime(self.path)
          except FileNotFoundError:
              return None
  
      def __repr__(self):
          return '%s(%s)' % (self.__class__.__name__, self.path)
  
  
  class KnownContentFileIO(FileIO):
      def __init__(self, path, content):
          super().__init__(path)
          self._content = content
  
      def read(self):
          return self._content
  