code: def test_functionality_es2():
      """Test es2 GL backend for basic functionality."""
      if True:
          raise SkipTest("Skip es2 functionality test for now.")
      if sys.platform.startswith("win"):
          raise SkipTest("Can only test es2 functionality on Windows.")
      _test_basics("es2")
  
file_path: vispy/vispy/gloo/gl/tests/test_basics.py
imports: import sys
  from vispy.app import Canvas
  from numpy.testing import assert_almost_equal
  from vispy.testing import requires_application, requires_pyopengl, SkipTest, run_tests_if_main, assert_equal, assert_true
  from vispy.util import use_log_level
  from vispy.gloo import gl
label_desc: Use image node_id 5 for calling a global function with example usage: test_functionality_es2() without return types