class_docstr: Reversible Layer.
class_docstr_tok: ["Reversible","Layer","."]
code: def has_backward(self):
      return True
  
imports: from absl import logging
  import jax
  from trax import fastmath
  from trax.layers import base
  from trax.layers import combinators
label_desc: Use image node_id 4 for calling the ReversibleLayer obj's underlying member method code with example usage: obj.has_backward() and returns: True