docs: def create_virtualenv(venv_dir, use_venv_module=True):
          """
          creates a new virtualenv in venv_dir
  
          By default, the built-in venv module is used.
          On older versions of python, you may set use_venv_module to False to use virtualenv
          """
  
          if not use_venv_module:
              try:
                  check_call(['virtualenv', venv_dir, '--no-site-packages'])
              except OSError:
                  raise Exception('You probably dont have virtualenv installed: sudo apt-get install python-virtualenv')
          else:
              check_call([sys.executable or 'python', '-m', 'venv', venv_dir])