'Legacy filter - new users specify individual filters'

def filter_default(self, browser):

    try:
        minimum_version = MIN_VERSIONS[browser['family']]
    except KeyError:
        return False
    try:
        major_browser_version = int(browser['major'])
    except (TypeError, ValueError):
        return False
    if (minimum_version > major_browser_version):
        return True
    return False
