docs: void onConsumedSubpartition(int subpartitionIndex) {
  
  		if (isReleased.get()) {
  			return;
  		}
  
  		int refCnt = pendingReferences.decrementAndGet();
  
  		if (refCnt == 0) {
  			partitionManager.onConsumedPartition(this);
  		}
  		else if (refCnt < 0) {
  			throw new IllegalStateException("All references released.");
  		}
  
  		LOG.debug("{}: Received release notification for subpartition {} (reference count now at: {}).",
  				this, subpartitionIndex, pendingReferences);
  	}