src/transformers/models/esm/modeling_esm.py/EsmContactPredictionHead/__init__
class EsmContactPredictionHead:    def __init__(
        self,
        in_features: int,
        bias=True,
        eos_idx: int = 2,
    ):
        super().__init__()
        self.in_features = in_features
        self.eos_idx = eos_idx
        self.regression = nn.Linear(in_features, 1, bias)
        self.activation = nn.Sigmoid()