poll(interval, url, args, cb, post) {
			if (interval !== null && interval <= 0)
				interval = env.pollinterval;

			const data = Object.assign(post ? { token: env.token } : {}, args);
			const method = post ? 'POST' : 'GET';

			if (!/^(?:\/|\S+:\/\/)/.test(url))
				url = this.url(url);

			if (interval !== null)
				return Request.poll.add(interval, url, { method, query: data }, cb);
			else
				return Request.request(url, { method, query: data })
					.then(res => {
						let json = null;
						if (/^application\/json\b/.test(res.headers.get('Content-Type')))
							try { json = res.json() } catch(e) {}
						cb(res.xhr, json, res.duration);
					});
		}
Register a polling HTTP request that invokes the specified
callback function. The function is a wrapper around
{@link LuCI.request.poll#add Request.poll.add()}.

@deprecated
@instance
@memberof LuCI

@param {number} interval
The poll interval to use. If set to a value less than or equal
to `0`, it will default to the global poll interval configured
in `LuCI.env.pollinterval`.

@param {string} url
The URL to request.

@param {Object<string, string>} [args]
Specifies additional arguments for the request. For GET requests,
the arguments are appended to the URL as query string, for POST
requests, they'll be added to the request body.

@param {LuCI.requestCallbackFn} cb
The callback function to invoke whenever a request finishes.

@param {boolean} [post=false]
When set to `false` or not specified, poll requests will be made
using the GET method. When set to `true`, POST requests will be
issued. In case of POST requests, the request body will contain
an argument `token` with the current value of `LuCI.env.token` by
default, regardless of the parameters specified with `args`.

@return {function}
Returns the internally created function that has been passed to
{@link LuCI.request.poll#add Request.poll.add()}. This value can
be passed to {@link LuCI.poll.remove Poll.remove()} to remove the
polling request.