code: def format(self, data: Iterable[_FormatArg]) -> bytes:
          
          fix_arg = self._fix_format_arg
          return self.how % tuple(fix_arg(item) for item in data)
docs: String interpolation into the format string.
  
          Args:
              data: The data interpolated into the format string.
  
          Examples:
              ::
  
                  BytesFormat(b'Hello, %b!') % b'World'
                  BytesFormat(b'%b, %b!') % (b'Hello', b'World')