code: private String splitNameWithoutGzipExtension(String split)
              throws IOException {
          if (split == null) {
              throw new IOException("Path is not a split");
          }
          if (split.endsWith(".gz")) {
              return split.substring(0, split.length() - 3);
          }
          return split;
      }
docs: Since we appended a gzip extension to the split file name we need to take it off to get the actual split.