How to use the ykdl.util.rangefetch_server.RangeFetch function in ykdl

def start_new_server(bind='', port=8806, first_size=None, max_size=None,
                     threads=None, down_rate=None, proxy=None, headers=None, **kwargs):
    if first_size:
        RangeFetch.first_size = first_size
    if max_size:
        RangeFetch.max_size = max_size
    if threads:
        RangeFetch.threads = threads
    if down_rate:
        RangeFetch.down_rate_min = int(down_rate * 2)
        RangeFetch.down_rate_max = RangeFetch.down_rate_min + min(max(down_rate, 1024 * 100), 1024 * 200)
    if proxy:
        RangeFetch.proxy = proxy
    if headers:
        RangeFetch.headers.update(headers)
    new_server = LocalTCPServer((bind, port), RangeFetchHandler)
    RangeFetch.bufsize = RangeFetchHandler.bufsize
    thread.start_new_thread(new_server.serve_forever, ())
    return new_server

def start_new_server(bind='', port=8806, first_size=None, max_size=None,
                     threads=None, down_rate=None, proxy=None, headers=None, **kwargs):
    if first_size:
        RangeFetch.first_size = first_size
    if max_size:
        RangeFetch.max_size = max_size
    if threads:
        RangeFetch.threads = threads
    if down_rate:
        RangeFetch.down_rate_min = int(down_rate * 2)
        RangeFetch.down_rate_max = RangeFetch.down_rate_min + min(max(down_rate, 1024 * 100), 1024 * 200)
    if proxy:
        RangeFetch.proxy = proxy
    if headers:
        RangeFetch.headers.update(headers)
    new_server = LocalTCPServer((bind, port), RangeFetchHandler)
    RangeFetch.bufsize = RangeFetchHandler.bufsize
    thread.start_new_thread(new_server.serve_forever, ())
    return new_server

def start_new_server(bind='', port=8806, first_size=None, max_size=None,
                     threads=None, down_rate=None, proxy=None, headers=None, **kwargs):
    if first_size:
        RangeFetch.first_size = first_size
    if max_size:
        RangeFetch.max_size = max_size
    if threads:
        RangeFetch.threads = threads
    if down_rate:
        RangeFetch.down_rate_min = int(down_rate * 2)
        RangeFetch.down_rate_max = RangeFetch.down_rate_min + min(max(down_rate, 1024 * 100), 1024 * 200)
    if proxy:
        RangeFetch.proxy = proxy
    if headers:
        RangeFetch.headers.update(headers)
    new_server = LocalTCPServer((bind, port), RangeFetchHandler)
    RangeFetch.bufsize = RangeFetchHandler.bufsize
    thread.start_new_thread(new_server.serve_forever, ())
    return new_server

threads=None, down_rate=None, proxy=None, headers=None, **kwargs):
    if first_size:
        RangeFetch.first_size = first_size
    if max_size:
        RangeFetch.max_size = max_size
    if threads:
        RangeFetch.threads = threads
    if down_rate:
        RangeFetch.down_rate_min = int(down_rate * 2)
        RangeFetch.down_rate_max = RangeFetch.down_rate_min + min(max(down_rate, 1024 * 100), 1024 * 200)
    if proxy:
        RangeFetch.proxy = proxy
    if headers:
        RangeFetch.headers.update(headers)
    new_server = LocalTCPServer((bind, port), RangeFetchHandler)
    RangeFetch.bufsize = RangeFetchHandler.bufsize
    thread.start_new_thread(new_server.serve_forever, ())
    return new_server

def start_new_server(bind='', port=8806, first_size=None, max_size=None,
                     threads=None, down_rate=None, proxy=None, headers=None, **kwargs):
    if first_size:
        RangeFetch.first_size = first_size
    if max_size:
        RangeFetch.max_size = max_size
    if threads:
        RangeFetch.threads = threads
    if down_rate:
        RangeFetch.down_rate_min = int(down_rate * 2)
        RangeFetch.down_rate_max = RangeFetch.down_rate_min + min(max(down_rate, 1024 * 100), 1024 * 200)
    if proxy:
        RangeFetch.proxy = proxy
    if headers:
        RangeFetch.headers.update(headers)
    new_server = LocalTCPServer((bind, port), RangeFetchHandler)
    RangeFetch.bufsize = RangeFetchHandler.bufsize
    thread.start_new_thread(new_server.serve_forever, ())
    return new_server

def start_new_server(bind='', port=8806, first_size=None, max_size=None,
                     threads=None, down_rate=None, proxy=None, headers=None, **kwargs):
    if first_size:
        RangeFetch.first_size = first_size
    if max_size:
        RangeFetch.max_size = max_size
    if threads:
        RangeFetch.threads = threads
    if down_rate:
        RangeFetch.down_rate_min = int(down_rate * 2)
        RangeFetch.down_rate_max = RangeFetch.down_rate_min + min(max(down_rate, 1024 * 100), 1024 * 200)
    if proxy:
        RangeFetch.proxy = proxy
    if headers:
        RangeFetch.headers.update(headers)
    new_server = LocalTCPServer((bind, port), RangeFetchHandler)
    RangeFetch.bufsize = RangeFetchHandler.bufsize
    thread.start_new_thread(new_server.serve_forever, ())
    return new_server

if ('range=' in url_parts.query or
            'live=1' in url_parts.query or
            'range/' in url_parts.path):
            self.send_error(500,
                'Range request not be accepted, range fetch can not be finished, url: %s' %  self.url)
            return

        request_range = self.headers.get('Range')
        if request_range:
            request_range = getbytes(request_range)
            range_start, range_end = [int(n) if n else 0 for n in request_range.group(1, 2)]
        else:
            range_start = range_end = 0

        RangeFetch(self, range_start, range_end).fetch()

def start_new_server(bind='', port=8806, first_size=None, max_size=None,
                     threads=None, down_rate=None, proxy=None, headers=None, **kwargs):
    if first_size:
        RangeFetch.first_size = first_size
    if max_size:
        RangeFetch.max_size = max_size
    if threads:
        RangeFetch.threads = threads
    if down_rate:
        RangeFetch.down_rate_min = int(down_rate * 2)
        RangeFetch.down_rate_max = RangeFetch.down_rate_min + min(max(down_rate, 1024 * 100), 1024 * 200)
    if proxy:
        RangeFetch.proxy = proxy
    if headers:
        RangeFetch.headers.update(headers)
    new_server = LocalTCPServer((bind, port), RangeFetchHandler)
    RangeFetch.bufsize = RangeFetchHandler.bufsize
    thread.start_new_thread(new_server.serve_forever, ())
    return new_server