code: private static int createWriteDFSPaths()
    {
  
    	if (createDFSPaths() != 0) {
    		return -1;
    	}
    	
  	  try {
  		  // write to all the files!
  	  	for (Map.Entry<String, OutputStream> file : files_.entrySet()) {
  	  		OutputStream os = file.getValue();
  
  	  		long startTime = System.nanoTime();
  	  		os.write(data_.getBytes());
          timingWrite_.add(new Double((System.nanoTime() - startTime)/(1E9)));
  	  		os.close();
  	  	}
  	  	
  	  } catch (IOException e) {
  	  	e.printStackTrace();
  	  	return -1;
  	  }
    	  	
    	return 0;
    }
docs: This creates DFS paths and writes data_ to them in one go.
  @return -1 on error, 0 on success