def getheaderAnim(self, im):
        """ getheaderAnim(im)

        Get animation header. To replace PILs getheader()[0]

        """
        bb = "GIF89a"
        bb += intToBin(im.size[0])
        bb += intToBin(im.size[1])
        bb += "\x87\x00\x00"
        return bb