code: def stack_data_given_key(predictions, key):
      x = [p[key] for p in predictions]
      x = np.stack(x, axis=0)
      return x
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import numpy
  import six
  import tensorflow.compat.v1
label_desc: Use image node_id 8 for calling a global function with example usage: stack_data_given_key(predictions, key) and returns: x