code: public void close() {
          Collection<WriterPoolMember> writers = drainAllWriters();
          for (WriterPoolMember writer: writers) {
              try {
                  destroyWriter(writer);
              } catch (IOException e) {
                  logger.log(Level.WARNING,"problem closing writer",e); 
              }
          }
      }
docs: Close all {@link WriterPoolMember}s in pool.