docs: public String dimensonsToString(String sep) {
      StringBuilder result = new StringBuilder(100).append('[');
      for(int dim = BitsUtil.nextSetBit(dimensions, 0); dim >= 0; dim = BitsUtil.nextSetBit(dimensions, dim + 1)) {
        result.append(dim + 1).append(sep);
      }
      if(result.length() > sep.length()) { // Un-append last separator
        result.setLength(result.length() - sep.length());
      }
      return result.append(']').toString();
    }