code: def _test_function_names(mod):
      # The .difference(['gl2']) is to allow the gl2 module name
      fnames = set([name for name in dir(mod) if name.startswith("gl")])
      assert function_names.difference(fnames) == set()
      assert (
          fnames.difference(function_names).difference(ok_names)
          == set()
      )
  
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 2 for calling a global function with example usage: _test_function_names(mod) without return types