entry (requestData, createIfMissing = false, cacheWhitelist = []) {
		if (!requestData.urlPath) {
			throw new Error("Missing requestData.urlPath");
		}

		logger.debug(`Getting ReactServerAgent request data cache entry for ${requestData.urlPath}`)

		var cacheEntry = this._findEntry(requestData);
		if (!cacheEntry && createIfMissing) {
			cacheEntry = this._addEntry(requestData, cacheWhitelist);
		}

		return cacheEntry;
	}
Get (optionally creating if necessary) the entry for the given
requestData from the cache.

@param createIfMissing boolean default false
@param cacheWhitelist array default []