src/transformers/models/xlnet/modeling_xlnet.py/XLNetFeedForward/__init__
class XLNetFeedForward:    def __init__(self, config):
        super().__init__()
        self.layer_norm = nn.LayerNorm(config.d_model, eps=config.layer_norm_eps)
        self.layer_1 = nn.Linear(config.d_model, config.d_inner)
        self.layer_2 = nn.Linear(config.d_inner, config.d_model)
        self.dropout = nn.Dropout(config.dropout)
        if isinstance(config.ff_activation, str):
            self.activation_function = ACT2FN[config.ff_activation]
        else:
            self.activation_function = config.ff_activation