code: def _concatenate_features(self, x: Dict):
      x = torch.cat(
          [x[key] for key in self.pick_keys if x[key] is not None], 1
      )
      return x
  
imports: from collections import namedtuple
  from typing import Dict
  import torch
  import torch.nn
  from omegaconf import DictConfig
  from ..base_model import SSLBaseModel
  from ..common.heads import MultiTaskHead
  from ..common.layers import MixedEmbedding1dLayer
  from ..common.noise_generators import SwapNoiseCorrupter
label_desc: Use image node_id 5 for calling the DenoisingAutoEncoderFeaturizer obj's underlying member method code with example usage: obj._concatenate_features(x) and returns: x