public static Set<StreamSpec> getStreamSpecs(Set<String> streamIds, StreamConfig streamConfig) {
    return streamIds.stream().map(streamId -> getStreamSpec(streamId, streamConfig)).collect(Collectors.toSet());
  }
Returns the period separated system stream name for the provided {@code systemStream}. For
example, SystemStream("kafka", "topic") would return "kafka.topic".

@param systemStream the {@link SystemStream} to get the name for
@return the system stream name
samza-core/src/main/java/org/apache/samza/util/StreamUtil.java