code: @Override
    public IoBuffer fill(int size) {
      autoExpand(size);
      int q = size >>> 3;
      int r = size & 7;
  
      for (int i = q; i > 0; i--) {
        putLong(0L);
      }
  
      q = r >>> 2;
      r = r & 3;
  
      if (q > 0) {
        putInt(0);
      }
  
      q = r >> 1;
      r = r & 1;
  
      if (q > 0) {
        putShort((short) 0);
      }
  
      if (r > 0) {
        put((byte) 0);
      }
  
      return this;
    }
docs: {@inheritDoc}