code: public RDD textFile(ExtractorConfig<Cells> config) throws IllegalArgumentException {
          if(ExtractorConstants.HDFS.equals(config.getExtractorImplClassName())) {
              return createHDFSRDD(config);
          } else if(ExtractorConstants.S3.equals(config.getExtractorImplClassName())) {
              return createS3RDD(config);
          }
          throw new IllegalArgumentException("Valid configurations are HDFS paths, S3 paths or local file paths.");
      }
docs: Returns a Cells RDD from a HDFS or S3 ExtractorConfig.
  @param config ExtractorConfig for HDFS or S3.
  @return RDD of Cells.
  @throws IllegalArgumentException