def get(url, session=None, silent=not debug, **kwargs):
    """Retrieve a given URL and log response.

    :param session: a :class:`requests.Session` object.
    :param silent: if **True**, response status and URL will not be printed.
    """
    session = session or requests
    kwargs["verify"] = kwargs.get("verify", True)
    r = session.get(url, **kwargs)
    if not silent:
        status_code = click.style(
            str(r.status_code),
            fg="green" if r.status_code in (200, 304) else "red")
        click.echo(status_code + " " + url)
        if r.status_code == 404:
            raise PackageNotFoundError
    return r
def reset_signal_handler(cls, signal_handler):
        """Class state:

        - Overwrites `cls._signal_handler`.
        OS state:
        - Overwrites signal handlers for SIGINT, SIGQUIT, and SIGTERM.

        NB: This method calls signal.signal(), which will crash if not called from the main thread!

        :returns: The :class:`SignalHandler` that was previously registered, or None if this is
                  the first time this method was called.
        """
        assert isinstance(signal_handler, SignalHandler)
        # NB: Modify process-global state!
        for signum, handler in signal_handler.signal_handler_mapping.items():
            signal.signal(signum, handler)
            # Retry any system calls interrupted by any of the signals we just installed handlers for
            # (instead of having them raise EINTR). siginterrupt(3) says this is the default behavior on
            # Linux and OSX.
            signal.siginterrupt(signum, False)

        previous_signal_handler = cls._signal_handler
        # NB: Mutate the class variables!
        cls._signal_handler = signal_handler
        return previous_signal_handler