code: def decoder(
      self, dec: _typing.Union[BaseDecoderMaintainer, str, None]
  ):
      if isinstance(self.encoder, BaseAutoModel):
          logging.warn("Ignore passed dec since enc is a whole model")
          self._decoder = None
          return
      if isinstance(dec, str):
          if self.node_level:
              self._decoder = DecoderUniversalRegistry.get_decoder(dec)(
                  self.last_dim,
                  input_dimension=self.last_dim,
                  device=self.device,
                  init=self.initialized,
              )
          elif self.graph_level:
              self._decoder = DecoderUniversalRegistry.get_decoder(dec)(
                  self.last_dim,
                  input_dimension=self.last_dim,
                  num_graph_features=self.num_graph_features,
                  device=self.device,
                  init=self.initialized,
              )
      elif isinstance(dec, BaseDecoderMaintainer) or dec is None:
          self._decoder = dec
      else:
          raise NotImplementedError(
              f"Sorry. The decoder {dec} is not supported yet."
          )
      self.num_features = self.num_features
      self.last_dim = self.last_dim
      self.num_graph_features = self.num_graph_features
  
imports: import os
  import torch
  import torch_geometric
  import logging
  import numpy
  import typing
  from tqdm import trange
  from typing import Union, Tuple, Sequence, Type, Callable
  import torch.nn.functional
  import torch.utils.data
  from torch.optim.lr_scheduler import StepLR, MultiStepLR, ExponentialLR, ReduceLROnPlateau
  from .losses import NTXent_loss
  from .utils import get_view_by_name
  from autogl.module.model.encoders.base_encoder import AutoHomogeneousEncoderMaintainer
  from ..base import BaseTrainer, EarlyStopping, _DummyModel
  from ..evaluation import Evaluation, get_feval, Acc
  from ...model import BaseAutoModel, BaseEncoderMaintainer, BaseDecoderMaintainer, EncoderUniversalRegistry, DecoderUniversalRegistry
  from ....utils import get_logger
  from ....datasets import utils
label_desc: Use image node_id 6 for calling the BaseContrastiveTrainer obj's underlying member method code with example usage: obj.decoder(dec) without return types