docs: public void add(PagedBitMap that) {
          LongArray ta = that.array;
          long n = 0;
          while(true) {
              n = ta.seekNext(n);
              if (n < 0) {
                  break;
              }
              long v = array.get(n) | ta.get(n);
              array.set(n, v);
              ++n;
          }
      }