protected static <K, V> boolean checkIfPresent(Map<K, V> config) {
    return config != null && !config.isEmpty();
  }
Given an instance name of the form hostname_port, returns a pair of <hostname, port>.
Given an instance name of the form hostname, returns a pair of <hostname, defaultPort>.
@param instanceName Name of the instance machine
@param defaultPort Default port used by machines
@return Pair of <hostname, port>
ambry-clustermap/src/main/java/com/github/ambry/clustermap/TaskUtils.java