src/transformers/models/opt/modeling_opt.py/OPTForQuestionAnswering/__init__
class OPTForQuestionAnswering:    def __init__(self, config: OPTConfig):
        super().__init__(config)
        self.model = OPTModel(config)
        self.qa_outputs = nn.Linear(config.word_embed_proj_dim, 2)

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