code: def install_dummy_glir():
      wrappers.get_current_canvas = lambda x=None: dummy_glir
      dummy_glir.clear()
      return dummy_glir
  
file_path: vispy/vispy/gloo/tests/test_wrappers.py
imports: import numpy
  from numpy.testing import assert_array_equal, assert_allclose
  from vispy import gloo
  from vispy.gloo import gl
  from vispy.app import Canvas
  from vispy.testing import requires_application, run_tests_if_main, assert_true, assert_equal, assert_raises
  from vispy.gloo import read_pixels
  from vispy.gloo.glir import GlirQueue
  from vispy.gloo import wrappers
label_desc: Use image node_id 1 for calling a global function with example usage: install_dummy_glir() and returns: dummy_glir