code: @Override
      public void initialize(InputSplit split) throws IOException, InterruptedException {
          if (split instanceof ListStringSplit) {
              ListStringSplit listStringSplit = (ListStringSplit) split;
              delimitedData = listStringSplit.getData();
              dataIter = delimitedData.iterator();
          } else {
              throw new IllegalArgumentException("Illegal type of input split " + split.getClass().getName());
          }
      }
docs: Called once at initialization.
  
  @param split the split that defines the range of records to read
  @throws IOException
  @throws InterruptedException