code: public void addr( NewChunk nc ) {
      long  [] tmpl = _ls; _ls = nc._ls; nc._ls = tmpl;
      int   [] tmpi = _xs; _xs = nc._xs; nc._xs = tmpi;
               tmpi = _id; _id = nc._id; nc._id = tmpi;
      double[] tmpd = _ds; _ds = nc._ds; nc._ds = tmpd;
      int      tmp  = _sparseLen; _sparseLen=nc._sparseLen; nc._sparseLen=tmp;
               tmp  = _len; _len = nc._len; nc._len = tmp;
      add(nc);
    }
docs: PREpend all of 'nc' onto the current NewChunk.  Kill nc.