src/transformers/models/ibert/modeling_ibert.py/IBertForMultipleChoice/__init__
class IBertForMultipleChoice:    def __init__(self, config):
        super().__init__(config)

        self.ibert = IBertModel(config)
        self.dropout = nn.Dropout(config.hidden_dropout_prob)
        self.classifier = nn.Linear(config.hidden_size, 1)

        self.init_weights()