code: static void replaceEntry(PollArrayWrapper source, int sindex,
                        PollArrayWrapper target, int tindex) {
          target.putDescriptor(tindex, source.getDescriptor(sindex));
          target.putEventOps(tindex, source.getEventOps(sindex));
          target.putReventOps(tindex, source.getReventOps(sindex));
      }
docs: Writes the pollfd entry from the source wrapper at the source index
  over the entry in the target wrapper at the target index. The source
  array remains unchanged unless the source array and the target are
  the same array.