code: def test_import_nothing():
      """Not importing vispy should not import any vispy modules."""
      modnames = loaded_vispy_modules("os", 2)
      assert_equal(modnames, set())
  
file_path: vispy/vispy/util/tests/test_import.py
imports: import sys
  import os
  from vispy.testing import assert_in, assert_not_in, requires_pyopengl, run_tests_if_main, assert_equal
  from vispy.util import run_subprocess
  import vispy
label_desc: Use image node_id 2 for calling a global function with example usage: test_import_nothing() without return types