code: def get_header_anim(self, im):
          
          bb = "GIF89a"
          bb += int_to_bin(im.size[0])
          bb += int_to_bin(im.size[1])
          bb += "\x87\x00\x00"
          return bb
docs: get_header_anim(im)
  
          Get animation header. To replace PILs getheader()[0]