class_docstr: Concatenate with padding operating on pairs to combine with rev-nets.
class_docstr_tok: ["Concatenate","with","padding","operating","on","pairs","to","combine","with","rev-nets","."]
code: def __init__(self, mode="train"):
      super().__init__(n_in=6, n_out=4)
      self._mode = mode
  
imports: from trax import fastmath
  from trax import layers
  from trax.fastmath import numpy
  from trax.models.research import configurable_transformer
label_desc: Use image node_id 1 to create a new ConcatWithPadding2 object from inherited base classes: tl with example: obj = ConcatWithPadding2(mode)