class_docstr: A class representing a hybrid approach of combining multiple
  representations into a single representation. Representations will be
  combined by concatenating them on dim=-1.
  
  Parameters
  ----------
  chain
      A list of representations. Elements must be of type Representation.
code: def __init__(self, chain: List, *args, **kwargs):
      super().__init__(*args, **kwargs)
      self.chain = chain
      for representation in self.chain:
          self.register_child(representation)
  
file_path: gluonts/src/gluonts/mx/representation/representation_chain.py
imports: from typing import List, Optional, Tuple
  import mxnet
  import numpy
  from gluonts.core.component import validated
  from gluonts.dataset.common import Dataset
  from gluonts.mx import Tensor
  from gluonts.mx.context import get_mxnet_context
  from .representation import Representation
label_desc: Use image node_id 1 to create a new RepresentationChain object from inherited base classes: Representation with example: obj = RepresentationChain(chain)