code: def test_glplus():
      """Run glplus, check that mo names, set back, check exact set of names."""
      gl.use_gl("gl+")
      # Check that there are more names
      fnames = set([name for name in dir(gl) if name.startswith("gl")])
      assert (
          len(fnames.difference(function_names).difference(["gl2"]))
          > 50
      )
      cnames = set([name for name in dir(gl) if name.startswith("GL")])
      assert len(cnames.difference(constant_names)) > 50
      gl.use_gl("gl2")
      _test_function_names(gl)
      _test_constant_names(gl)
  
file_path: vispy/vispy/gloo/gl/tests/test_names.py
imports: from vispy.testing import requires_pyopengl
  from vispy.gloo import gl
  from vispy.testing import run_tests_if_main
label_desc: Use image node_id 7 for calling a global function with example usage: test_glplus() without return types