code: private Path getFilePath(String segmentName, long epoch) {
          Preconditions.checkState(segmentName != null && segmentName.length() > 0, "segmentName must be non-null and non-empty");
          Preconditions.checkState(epoch >= 0, "epoch must be non-negative " + epoch);
          return new Path(String.format(NAME_FORMAT, getPathPrefix(segmentName), epoch));
      }
docs: Gets the full HDFS Path to a file for the given Segment, startOffset and epoch.