data_text like this:
traindata = {
‘text’: [
‘我们有一个愉快的星期天’,
‘我们明天去吃饭？’,
‘我们有英语课程’,
‘我们明天出去玩吧’,
‘哈哈哈，今天是星期二’
]}
when make MLM model train data，mask traindata  as the model input, origin traindata as the label.
for example:
input=‘我们[MASK]天出去玩吧’, //mask position is random.
label=‘我们明天出去玩吧’