code: def _cell_list(
      unit_type,
      num_units,
      num_layers,
      num_residual_layers,
      forget_bias,
      dropout,
      mode,
      num_gpus,
      base_gpu=0,
      single_cell_fn=None,
      residual_fn=None,
  ):
      """Create a list of RNN cells."""
      if not single_cell_fn:
          single_cell_fn = _single_cell
  
      # Multi-GPU
      cell_list = []
      for i in range(num_layers):
          utils.print_out("  cell %d" % i, new_line=False)
          single_cell = single_cell_fn(
              unit_type=unit_type,
              num_units=num_units,
              forget_bias=forget_bias,
              dropout=dropout,
              mode=mode,
              residual_connection=(
                  i >= num_layers - num_residual_layers
              ),
              device_str=get_device_str(i + base_gpu, num_gpus),
              residual_fn=residual_fn,
          )
          utils.print_out("")
          cell_list.append(single_cell)
  
      return cell_list
  
imports: from __future__ import print_function
  import collections
  import os
  import time
  import numpy
  import six
  import tensorflow
  from tensorflow.python.ops import lookup_ops
  from .utils import misc_utils, vocab_utils, iterator_utils
label_desc: Use image node_id 11 for calling a global function with example usage: _cell_list(unit_type, num_units, num_layers, num_residual_layers, forget_bias, dropout, mode, num_gpus, base_gpu, single_cell_fn, residual_fn) and returns: cell_list