code: public static Roaring64NavigableMap bitmapOf(final long... dat) {
      final Roaring64NavigableMap ans = new Roaring64NavigableMap();
      ans.add(dat);
      return ans;
    }
docs: Generate a bitmap with the specified values set to true. The provided longs values don't have
  to be in sorted order, but it may be preferable to sort them from a performance point of view.
  
  @param dat set values
  @return a new bitmap