generateItemSnapshot(item, key) {
		const snapshot = {
			key,
			labels: item.labels,
			count: item.count,
			sum: item.sum,
			lastValue: item.lastValue,
			timestamp: item.timestamp
		};

		if (this.buckets)
			snapshot.buckets = this.buckets.reduce(
				(a, b) => setProp(a, b, item.bucketValues[b]),
				{}
			);

		if (this.quantiles) Object.assign(snapshot, item.quantileValues.snapshot());

		if (item.rate) snapshot.rate = item.rate.rate;

		return snapshot;
	}
Generate a snapshot for an item

@param {Object} item
@param {String} key
@returns {Object}
@memberof HistogramMetric