@staticmethod
def prefix(url, csv_url):
    """ :return prefix of uri template - the part before {...}"""
    if url.startswith('http'):
        key = url[url.find('{') + 1:url.find('}')]
        if key.startswith('#'):
            url = url[:url.find('#') + 1]
            return url.replace('{', '')
        else:
            return url[:url.find('{')]
    else:
        return csv_url + url[:url.find('{')]
