src/transformers/models/mpnet/modeling_mpnet.py/MPNetForMaskedLM/__init__
class MPNetForMaskedLM:    def __init__(self, config):
        super().__init__(config)

        self.mpnet = MPNetModel(config, add_pooling_layer=False)
        self.lm_head = MPNetLMHead(config)

        # Initialize weights and apply final processing
        self.post_init()