code: def watch_variable(tape, variable):
      """Marks this variable to be watched by the given tape."""
      variables = _variables_override(variable)
      for var in variables:
          pywrap_tfe.TFE_Py_TapeWatchVariable(
              tape._tape, var
          )  # pylint: disable=protected-access
          pywrap_tfe.TFE_Py_VariableWatcherVariableAccessed(var)
  
file_path: tensorflow/tensorflow/python/eager/tape.py
imports: from tensorflow.python import pywrap_tfe
label_desc: Use image node_id 6 for calling a global function with example usage: watch_variable(tape, variable) without return types