src/transformers/models/prophetnet/modeling_prophetnet.py/ProphetNetPositionalEmbeddings/__init__
class ProphetNetPositionalEmbeddings:    def __init__(self, config: ProphetNetConfig) -> None:
        self.max_length = config.max_position_embeddings
        super().__init__(config.max_position_embeddings, config.hidden_size, config.pad_token_id)