def browse(request, classifiers):
    """
    Retrieve a list of (name, version) pairs of all releases classified
    with all of the given classifiers. 'classifiers' must be a list of
    Trove classifier strings.

    changelog(since)
    Retrieve a list of four-tuples (name, version, timestamp, action)
    since the given timestamp. All timestamps are UTC values.
    The argument is a UTC integer seconds since the epoch.
    """
    session = DBSession()
    release = Release.by_classifiers(session, classifiers)
    rv = [(r.package.name, r.version) for r in release]
    return rv