src/transformers/models/blenderbot/modeling_blenderbot.py/BlenderbotForCausalLM/__init__
class BlenderbotForCausalLM:    def __init__(self, config):
        config = copy.deepcopy(config)
        config.is_decoder = True
        config.is_encoder_decoder = False
        super().__init__(config)
        self.model = BlenderbotDecoderWrapper(config)

        self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)

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