class_docstr: Adaptive Computation Time Function to help we use nn.scan on ACT.
code: def __call__(self, carry_in, _) -> Any:
      if self.is_mutable_collection("params"):  # Init-mode
          carry_out, scan_out = self.take_a_step(carry_in)
      else:
          decision = self.stop_fn(carry_in)
          carry_out, scan_out = nn.cond(
              decision,
              self.skip_a_step,
              self.take_a_step,
              self,
              carry_in,
          )
      return carry_out, scan_out
  
imports: from typing import Any, Callable, Optional, Sequence, Tuple
  from absl import logging
  import flax.linen
  import jax
  import jax.numpy
  import ml_collections
  from scenic.model_lib.layers import nn_layers
label_desc: Use image node_id 6 for calling the ACTFunction obj's underlying member method code with example usage: obj.__call__(carry_in, _) and returns: carry_out,  scan_out