src/transformers/models/perceiver/modeling_perceiver.py/PerceiverMLP/__init__
class PerceiverMLP:    def __init__(self, config, input_size, widening_factor):
        super().__init__()
        self.dense1 = nn.Linear(input_size, widening_factor * input_size)
        if isinstance(config.hidden_act, str):
            self.intermediate_act_fn = ACT2FN[config.hidden_act]
        else:
            self.intermediate_act_fn = config.hidden_act
        self.dense2 = nn.Linear(widening_factor * input_size, input_size)