code: def echo(request):
      oldvalue = ipywidgets.widgets.widget.JUPYTER_WIDGETS_ECHO
      ipywidgets.widgets.widget.JUPYTER_WIDGETS_ECHO = request.param
      yield request.param
      ipywidgets.widgets.widget.JUPYTER_WIDGETS_ECHO = oldvalue
  
imports: import pytest
  from unittest import mock
  from traitlets import Bool, Tuple, List, Instance, CFloat, CInt, Float, Int, TraitError, observe
  from .utils import setup, teardown
  import ipywidgets
  from ipywidgets import Widget
label_desc: Use image node_id 1 for calling a global function with example usage: echo(request) without return types