src/transformers/models/vit/modeling_vit.py/ViTEncoder/__init__
class ViTEncoder:    def __init__(self, config: ViTConfig) -> None:
        super().__init__()
        self.config = config
        self.layer = nn.ModuleList([ViTLayer(config) for _ in range(config.num_hidden_layers)])
        self.gradient_checkpointing = False