class_docstr: Concatenates two length padded (B, L, H) arrays (of different lenghts).
class_docstr_tok: ["Concatenates","two","length","padded","(","B",",","L",",","H",")","arrays","(","of","different","lenghts",")","."]
code: def __init__(self, mode="train"):
      super().__init__(n_in=5, n_out=3)
      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 ConcatWithPadding object from inherited base classes: tl with example: obj = ConcatWithPadding(mode)