getWithTTL(key) {
		this.logger.debug(`GET ${key}`);
		let data = null;
		let ttl = null;
		if (this.cache.has(key)) {
			this.logger.debug(`FOUND ${key}`);

			let item = this.cache.get(key);
			let now = Date.now();
			ttl = (item.expire - now) / 1000;
			ttl = ttl > 0 ? ttl : null;
			if (this.opts.ttl) {
				// Update expire time (hold in the cache if we are using it)
				item.expire = now + this.opts.ttl * 1000;
			}
			data = this.clone ? this.clone(item.data) : item.data;
		}
		return this.broker.Promise.resolve({ data, ttl });
	}
Get data and ttl from cache by key.

@param {string|Array<string>} key
@returns {Promise}

@memberof MemoryCacher