code: def enable_control_flow_v2():  # pylint: disable=invalid-name
      """Use control flow v2.
  
      control flow v2 (cfv2) is an improved version of control flow in TensorFlow
      with support for higher order derivatives. Enabling cfv2 will change the
      graph/function representation of control flow, e.g., `tf.while_loop` and
      `tf.cond` will generate functional `While` and `If` ops instead of low-level
      `Switch`, `Merge` etc. ops. Note: Importing and running graphs exported
      with old control flow will still be supported.
  
      Calling tf.enable_control_flow_v2() lets you opt-in to this TensorFlow 2.0
      feature.
  
      Note: v2 control flow is always enabled inside of tf.function. Calling this
      function is not required.
      """
      # pylint: disable=protected-access
      logging.vlog(1, "Enabling control flow v2")
      ops._control_flow_api_gauge.get_cell().set(True)
      control_flow_util.ENABLE_CONTROL_FLOW_V2 = True
  
imports: from tensorflow.python.framework import ops
  from tensorflow.python.ops import control_flow_util
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 1 for calling a global function with example usage: enable_control_flow_v2() without return types