code: function validateSnapshotStorage(snapshotStorage) {
  	if (typeof snapshotStorage !== 'object' || !snapshotStorage)
  		throw new TypeError('snapshotStorage argument must be an Object');
  	if (typeof snapshotStorage.getAggregateSnapshot !== 'function')
  		throw new TypeError('snapshotStorage.getAggregateSnapshot argument must be a Function');
  	if (typeof snapshotStorage.saveAggregateSnapshot !== 'function')
  		throw new TypeError('snapshotStorage.saveAggregateSnapshot argument must be a Function');
  }
docs: Ensure snapshotStorage matches the expected format
  @param {IAggregateSnapshotStorage} snapshotStorage