code: def itersizes(self):
      sizes = []
      for size, fmts in self.SIZES.items():
          for fmt, reader in fmts:
              if fmt in self.dct:
                  sizes.append(size)
                  break
      return sizes
  
imports: import io
  import os
  import struct
  import sys
  from PIL import Image, ImageFile, PngImagePlugin, features
label_desc: Use image node_id 2 for calling the IcnsFile obj's underlying member method code with example usage: obj.itersizes() and returns: sizes