code: def _open(self):
      if not _accept(self.fp.read(4)):
          msg = "not a QOI file"
          raise SyntaxError(msg)
  
      self._size = tuple(i32(self.fp.read(4)) for i in range(2))
  
      channels = self.fp.read(1)[0]
      self._mode = "RGB" if channels == 3 else "RGBA"
  
      self.fp.seek(1, os.SEEK_CUR)  # colorspace
      self.tile = [("qoi", (0, 0) + self._size, self.fp.tell(), None)]
  
file_path: pillow/src/PIL/QoiImagePlugin.py
imports: from __future__ import annotations
  import os
  from .None import Image, ImageFile
  from ._binary import i32be
  from ._binary import o8
label_desc: Use image node_id 1 for calling the QoiImageFile obj's underlying member method code with example usage: obj._open() without return types