code: public HDFSDistributor setFileRoot(String fileRoot) {
          this.hdfsFileRoot = fileRoot;
          this.mapperInputFilePath = new Path(hdfsFileRoot + "/input.dat");
          if (mapperOutputFileName != null) {
              this.mapperOutputFilePath = new Path(hdfsFileRoot + "/" + mapperOutputFileName);
          }
          return this;
      }
docs: Set the file root on HDFS where files (temp and final) can be written
  
  @param fileRoot A valid HDFS location with space for the output of the data generation
  @return An updated HDFSDistributor with hdfsFileRoot set