code: function getKinesis(region) {
    const regionKey = getRegionKey(region);
    return regionKey ? kinesisByRegionKey.get(regionKey) : undefined;
  }
docs: Gets the Kinesis instance cached for the given region (if specified and if previously cached); otherwise for the
  current region (if previously cached); otherwise returns undefined.
  @param {string} [region] - the optional AWS region to use - defaults to current AWS region if not specified
  @returns {AWS.Kinesis|undefined} the Kinesis instance cached for the given or current region (if any); otherwise
  returns undefined