def get_labels(self): """See base class.""" return ["X","O", "B-R", "I-R","B-M","I-M","B-S","I-S","B-W","I-W"] O表示正常，X表示什么呀？
def get_labels(self):
"""See base class."""
return ["X","O", "B-R", "I-R","B-M","I-M","B-S","I-S","B-W","I-W"]
O表示正常，X表示什么呀？