src/transformers/models/roberta/modeling_roberta.py/RobertaForQuestionAnswering/__init__
class RobertaForQuestionAnswering:    def __init__(self, config):
        super().__init__(config)
        self.num_labels = config.num_labels

        self.roberta = RobertaModel(config, add_pooling_layer=False)
        self.qa_outputs = nn.Linear(config.hidden_size, config.num_labels)

        self.init_weights()