_startProcessing(entry) {
		this.hooks.beforeStart.callAsync(entry.item, err => {
			if (err) {
				this._handleResult(
					entry,
					makeWebpackError(err, `AsyncQueue(${this._name}).hooks.beforeStart`)
				);
				return;
			}
			let inCallback = false;
			try {
				this._processor(entry.item, (e, r) => {
					inCallback = true;
					this._handleResult(entry, e, r);
				});
			} catch (err) {
				if (inCallback) throw err;
				this._handleResult(entry, /** @type {WebpackError} */ (err), null);
			}
			this.hooks.started.call(entry.item);
		});
	}
@param {AsyncQueueEntry<T, K, R>} entry the entry
@returns {void}