src/transformers/models/funnel/modeling_funnel.py/FunnelEncoder/__init__
class FunnelEncoder:    def __init__(self, config: FunnelConfig) -> None:
        super().__init__()
        self.config = config
        self.attention_structure = FunnelAttentionStructure(config)
        self.blocks = nn.ModuleList(
            [
                nn.ModuleList([FunnelLayer(config, block_index) for _ in range(block_size)])
                for block_index, block_size in enumerate(config.block_sizes)
            ]
        )