def METHOD_NAME(disk_cache):
    """Test if entries inserted into the cache are actually there."""
    url = 'http://qutebrowser.org'
    content = b'foobar'
    assert disk_cache.cacheSize() == 0
    preload_cache(disk_cache, url, content)
    assert disk_cache.cacheSize() != 0
    assert disk_cache.data(QUrl(url)).readAll() == content