def user_agent(style=None) -> _UserAgent:
global useragent<EOL>if (not useragent) and style:<EOL><INDENT>useragent = UserAgent()<EOL><DEDENT>return useragent[style] if style else DEFAULT_USER_AGENT<EOL>
Returns an apparently legit user-agent, if not requested one of a specific
    style. Defaults to a Chrome-style User-Agent.