code: def dataset_single_var_loop(ds):
      s = tf.constant(0, dtype=tf.int64)
      for e in ds:
          s = s * 10 + e
      return s
  
imports: import tensorflow
  from tensorflow.python.autograph.tests import reference_test_base
label_desc: Use image node_id 3 for calling a global function with example usage: dataset_single_var_loop(ds) and returns: s