def METHOD_NAME(metafunc):
    """Override pytest's default test collection function.
    For each test in this directory which uses the `env_browser` fixture,
    the given test is called once for each value found in the
    `E2E_WEBDRIVER_BROWSERS` environment variable.
    """
    if 'env_browser' in metafunc.fixturenames:
        # In Python 2.7 the fallback kwarg of os.environ.get is `failobj`,
        # in 3.x it's `default`.
        browsers = os.environ.get('E2E_WEBDRIVER_BROWSERS',
                                  'Firefox').split()
        metafunc.parametrize('env_browser', browsers, indirect=True)