How to use the virtualenv.Logger.level_for_integer function in virtualenv

def create_environment():
    dest_dir = os.path.join(DIRNAME, CONFIG['virtualenv']['dest_dir'])
    dest_dir = os.path.abspath(dest_dir)

    # Create new virtual environment
    print('Step 1. Create new virtual environment')

    if not os.path.isdir(dest_dir) or CONFIG['virtualenv']['clear']:
        kwargs = copy.copy(CONFIG['virtualenv'])
        kwargs['home_dir'] = kwargs['dest_dir']

        verbosity = int(kwargs['verbose']) - int(kwargs['quiet'])
        logger = virtualenv.Logger([
            (virtualenv.Logger.level_for_integer(2 - verbosity), sys.stdout),
        ])

        del kwargs['dest_dir'], kwargs['quiet'], kwargs['verbose']

        virtualenv.logger = logger
        virtualenv.create_environment(**kwargs)
    else:
        print('Virtual environment %r already exists.' % \
              CONFIG['virtualenv']['dest_dir'])

def create(self):
        # Create new virtual environment
        print('\nStep 1. Create new virtual environment')

        if not os.path.isdir(self.dest_dir) or CONFIG['virtualenv']['clear']:
            kwargs = copy.copy(CONFIG['virtualenv'])
            kwargs['home_dir'] = self.dest_dir

            verbosity = int(kwargs['verbose']) - int(kwargs['quiet'])
            logger = virtualenv.Logger([
                (virtualenv.Logger.level_for_integer(2 - verbosity),
                 sys.stdout),
            ])

            del kwargs['dest_dir'], kwargs['quiet'], kwargs['verbose']

            virtualenv.logger = logger
            virtualenv.create_environment(**kwargs)
        else:
            print('Virtual environment %r already exists.' % self.dest_dir)

dest='distribute',
        action='store_true',
        help="Backward compatibility. Does nothing.")

    if 'extend_parser' in globals():
        extend_parser(parser)

    options, args = parser.parse_args()

    global logger

    if 'adjust_options' in globals():
        adjust_options(options, args)

    verbosity = options.verbose - options.quiet
    logger = Logger([(Logger.level_for_integer(2 - verbosity), sys.stdout)])

    if options.python and not os.environ.get('VIRTUALENV_INTERPRETER_RUNNING'):
        env = os.environ.copy()
        interpreter = resolve_interpreter(options.python)
        if interpreter == sys.executable:
            logger.warn('Already using interpreter %s' % interpreter)
        else:
            logger.notify('Running virtualenv with interpreter %s' % interpreter)
            env['VIRTUALENV_INTERPRETER_RUNNING'] = 'true'
            file = __file__
            if file.endswith('.pyc'):
                file = file[:-1]
            popen = subprocess.Popen([interpreter, file] + sys.argv[1:], env=env)
            raise SystemExit(popen.wait())

    if not args:

'--prompt',
        dest='prompt',
        help='Provides an alternative prompt prefix for this environment')

    if 'extend_parser' in globals():
        extend_parser(parser)

    options, args = parser.parse_args()

    global logger

    if 'adjust_options' in globals():
        adjust_options(options, args)

    verbosity = options.verbose - options.quiet
    logger = Logger([(Logger.level_for_integer(2 - verbosity), sys.stdout)])

    if options.python and not os.environ.get('VIRTUALENV_INTERPRETER_RUNNING'):
        env = os.environ.copy()
        interpreter = resolve_interpreter(options.python)
        if interpreter == sys.executable:
            logger.warn('Already using interpreter %s' % interpreter)
        else:
            logger.notify('Running virtualenv with interpreter %s' % interpreter)
            env['VIRTUALENV_INTERPRETER_RUNNING'] = 'true'
            file = __file__
            if file.endswith('.pyc'):
                file = file[:-1]
            popen = subprocess.Popen([interpreter, file] + sys.argv[1:], env=env)
            raise SystemExit(popen.wait())

    # Force --distribute on Python 3, since setuptools is not available.

finally:
                sys.argv[:] = orig_argv
        else:
            try:
                import virtualenv
            except ImportError:
                raise errors.DistutilsModuleError(
                    'The virtualenv module must be available if no virtualenv '
                    'bootstrap script is given: {0}'.format(bootstrap))
            self.logger.info(
                'Setting up a isolated Python with module: '
                '{0}.create_environment({1} {2})'.format(
                    virtualenv, repr(home_dir), ' '.join(
                        '{0}={1}'.format(item) for item in opts.items())))
            virtualenv.logger = virtualenv.Logger([(
                virtualenv.Logger.level_for_integer(2 - self.verbose),
                sys.stdout)])

            virtualenv.create_environment(home_dir, **opts)

        return os.path.join(
            sysconfig.get_path('scripts', vars=dict(base=home_dir)),
            'python' + sysconfig.get_config_var('EXE'))

def reset_python_environment(self):
        """
        Reset the python environment.
        """
        path = self.root_path
        if not exists(path):
            return False
        virtualenv.logger = virtualenv.Logger(
            [(virtualenv.Logger.level_for_integer(2), sys.stdout)])
        virtualenv.create_environment(path, site_packages=False)
        return True

def create_environment(path, config_ori):
    """Create environment structure.
    """
    # Archivo de configuracion destino
    config_dst = join(path, 'etc', config_filename)

    if not exists(path) or not listdir(path):
        # Crea el ambiente python
        virtualenv.logger = virtualenv.Logger(
            [(virtualenv.Logger.level_for_integer(2), sys.stdout)])
        virtualenv.create_environment(path, site_packages=False)

        # Crea el directorio donde va el archivo de configuracion
        makedirs(dirname(config_dst))

        # Descarga el archivo de configuracion environment.yml
        urlretrieve(config_ori, config_dst)

    # Prepara el ambiente Odoo
    env = OdooEnvironment(path)
    env.setup()

    return env