code: public StreamStateHandle closeAndGetSecondaryHandle() throws IOException {
  		if (secondaryStreamException == null) {
  			flushInternalBuffer();
  			return secondaryOutputStream.closeAndGetHandle();
  		} else {
  			throw new IOException("Secondary stream previously failed exceptionally", secondaryStreamException);
  		}
  	}
docs: Returns the state handle from the {@link #secondaryOutputStream}. Also reports suppressed exceptions from earlier
  interactions with that stream.