code: private Set<Integer> reportMatchAndFindIndexesToRemove(
  			Integer earliestTimestampLineIndex,
  			NmeaMessageExactEarthTimestamp timestamp,
  			Integer lowestTimeDiffIndex) {
  		String msg = getLine(lowestTimeDiffIndex);
  		log.debug("found matching msg=" + msg);
  		listener.message(msg, timestamp.getTime());
  		int maxIndex = Math
  				.max(lowestTimeDiffIndex, earliestTimestampLineIndex);
  		int minIndex = Math
  				.min(lowestTimeDiffIndex, earliestTimestampLineIndex);
  
  		// now remove from lists must remove bigger index first,
  		// otherwise indexes will change
  		return Sets.newHashSet(minIndex, maxIndex);
  	}
docs: Reports a found match and returns the indexes that can be removed from
  the buffer.
  
  @param earliestTimestampLineIndex
  @param timestamp
  @param lowestTimeDiffIndex
  @return