class_docstr: Series decomposition block
class_docstr_tok: ["Series","decomposition","block"]
code: def forward(self, x):
      moving_mean = self.moving_avg(x)
      res = x - moving_mean
      return res, moving_mean
  
imports: from typing import Optional, Tuple
  import torch
  import torch.nn
  from darts.logging import raise_if
  from darts.models.forecasting.pl_forecasting_module import PLMixedCovariatesModule, io_processor
  from darts.models.forecasting.torch_forecasting_model import MixedCovariatesTorchModel
label_desc: Use image node_id 2 for calling the _SeriesDecomp obj's underlying member method code with example usage: obj.forward(x) and returns: res,  moving_mean