docs: def _open_file(self, filename):
          """Open a file to be tailed"""
          if not self._os_is_windows:
              self._fh = open(filename, "rb")
              self.filename = filename
  
              self._fh.seek(0, os.SEEK_SET)
              self.oldsize = 0
              return
  
          # if we're in Windows, we need to use the WIN32 API to open the
          # file without locking it
          import win32file
          import msvcrt
  
          handle = win32file.CreateFile(filename,
                                        win32file.GENERIC_READ,
                                        win32file.FILE_SHARE_DELETE |
                                        win32file.FILE_SHARE_READ |
                                        win32file.FILE_SHARE_WRITE,
                                        None,
                                        win32file.OPEN_EXISTING,
                                        0,
                                        None)
          detached_handle = handle.Detach()
          file_descriptor = msvcrt.open_osfhandle(
              detached_handle, os.O_RDONLY)
  
          self._fh = open(file_descriptor, "rb")
          self.filename = filename
  
          self._fh.seek(0, os.SEEK_SET)
          self.oldsize = 0