class_docstr: A scope that tracks all trainable variable accesses within it.
  
  This explicitly ignores variables that are not marked as trainable.
  
  Sample usage:
  
  var = tf.Variable(0.0)
  with VariableWatcher() as variable_watcher:
    var.assign_add(1.0)
  
  assert variable_watcher.watched_variables == [var]
code: def __init__(self):
      self._variable_watcher = None
  
file_path: tensorflow-upstream/tensorflow/python/eager/record.py
imports: import contextlib
  from tensorflow.python import pywrap_tfe
label_desc: Use image node_id 1 to create a new VariableWatcher object from inherited base classes: object with example: obj = VariableWatcher()