src/transformers/models/funnel/modeling_funnel.py/FunnelLayer/__init__
class FunnelLayer:    def __init__(self, config: FunnelConfig, block_index: int) -> None:
        super().__init__()
        self.attention = FunnelRelMultiheadAttention(config, block_index)
        self.ffn = FunnelPositionwiseFFN(config)