code: def from_filename(filename, require=None):
      
      with io.open(filename, 'r', encoding='utf-8') as json_file:
          data = json.load(json_file)
          return data, from_dict(data, require=require)
docs: Reads a Google service account JSON file and returns its parsed info.
  
      Args:
          filename (str): The path to the service account .json file.
          require (Sequence[str]): List of keys required to be present in the
              info.
  
      Returns:
          Tuple[ Mapping[str, str], google.auth.crypt.Signer ]: The verified
              info and a signer instance.