code: public void close() throws IOException {
          if (!_closed) {
              try {
                  flush();
              } catch (Throwable t) {
                  LOG.debug(t.getMessage(), t);
              }
              _closed = true;
              super.close();
          }
      }
docs: /*
  (non-Javadoc)
  
  @see java.io.OutputStream#close()