code: def test_interact_existing_parent():
      lastValue = None
  
      def a():
          nonlocal lastValue
          lastValue = 5
  
      parent = Parameter.create(name="parent", type="group")
      outParam = interact(a, parent=parent)
      assert outParam in parent.names.values()
      outParam.activate()
      assert lastValue == 5
  
imports: from functools import wraps
  import numpy
  import pyqtgraph
  import pytest
  from pyqtgraph import functions
  from pyqtgraph.parametertree import InteractiveFunction, Interactor, interact, RunOptions
  from pyqtgraph.parametertree import Parameter
  from pyqtgraph.parametertree.Parameter import PARAM_TYPES
  from pyqtgraph.parametertree.parameterTypes import GroupParameter
  from pyqtgraph.Qt import QtGui
label_desc: Use image node_id 21 for calling a global function with example usage: test_interact_existing_parent() without return types