class Request(object_ref):

? ? def __init__(self, url, callback=None, method='GET', headers=None, body=None,
? ? ? ? ? ? ? ? ?cookies=None, meta=None, encoding='utf-8', priority=0,
? ? ? ? ? ? ? ? ?dont_filter=False, errback=None, flags=None, cb_kwargs=None):

? ? ? ? self._encoding = encoding ?# this one has to be set first
? ? ? ? self.method = str(method).upper()
? ? ? ? self._set_url(url)
? ? ? ? self._set_body(body)
? ? ? ? if not isinstance(priority, int):
? ? ? ? ? ? raise TypeError(f"Request priority not an integer: {priority!r}")
? ? ? ? self.priority = priority

? ? ? ? if callback is not None and not callable(callback):
? ? ? ? ? ? raise TypeError(f'callback must be a callable, got {type(callback).__name__}')
? ? ? ? if errback is not None and not callable(errback):
? ? ? ? ? ? raise TypeError(f'errback must be a callable, got {type(errback).__name__}')
? ? ? ? self.callback = callback
? ? ? ? self.errback = errback

? ? ? ? self.cookies = cookies or {}
? ? ? ? self.headers = Headers(headers or {}, encoding=encoding)
? ? ? ? self.dont_filter = dont_filter

? ? ? ? self._meta = dict(meta) if meta else None
? ? ? ? self._cb_kwargs = dict(cb_kwargs) if cb_kwargs else None
? ? ? ? self.flags = [] if flags is None else list(flags)