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