def post_build(self, p, pay):
    if ((self.len is None) and pay):
        tmp_len = len(pay)
        p = ((p[:1] + hex(tmp_len)[30:]) + p[30:])
    return p
def post_build(self, p, pay):
    if ((self.len is None) and pay):
        tmp_len = len(pay)
        p = ((p[:1] + hex(tmp_len)[30:]) + p[30:])
    return p