code: def _open(self) -> None:
      # check magic
      assert self.fp is not None
  
      if not _accept(self.fp.read(6)):
          msg = "not an XV thumbnail file"
          raise SyntaxError(msg)
  
      # Skip to beginning of next line
      self.fp.readline()
  
      # skip info comments
      while True:
          s = self.fp.readline()
          if not s:
              msg = "Unexpected EOF reading XV thumbnail file"
              raise SyntaxError(msg)
          if s[0] != 35:  # ie. when not a comment: '#'
              break
  
      # parse header line (already read)
      s = s.strip().split()
  
      self._mode = "P"
      self._size = int(s[0]), int(s[1])
  
      self.palette = ImagePalette.raw("RGB", PALETTE)
  
      self.tile = [
          ("raw", (0, 0) + self.size, self.fp.tell(), (self.mode, 0, 1))
      ]
  
imports: from __future__ import annotations
  from .None import Image, ImageFile, ImagePalette
  from ._binary import o8
label_desc: Use image node_id 1 for calling the XVThumbImageFile obj's underlying member method code with example usage: obj._open() without return types