def init_weights(self) -> None:
        """Initialize position embedding and mask token of MixMIM decoder."""
        super(MAEPretrainDecoder, self).init_weights()

        decoder_pos_embed = build_2d_sincos_position_embedding(
            int(self.num_patches**.5),
            self.decoder_pos_embed.shape[-1],
            cls_token=False)
        self.decoder_pos_embed.data.copy_(decoder_pos_embed.float())

        torch.nn.init.normal_(self.mask_token, std=.02)
Initialize position embedding and mask token of MixMIM decoder.
mmpretrain/models/necks/mixmim_neck.py