'Check the "secure" embed is safe to embed, and not a placeholder'

def validate_secure_oembed(self, oembed):

    if (not oembed.get('html')):
        return False
    iframe_src = lxml.html.fromstring(oembed['html']).get('src')
    if (not iframe_src):
        return False
    iframe_src_url = UrlParser(iframe_src)
    provider_src_url = UrlParser(iframe_src_url.query_dict.get('src'))
    return ((not provider_src_url.scheme) or (provider_src_url.scheme == 'https'))
