code: function(separator, digits) {
  			separator = separator || ".";
  			var s,
  				res = [];
  			$.each(this.getParentList(false, true), function(i, o) {
  				s = "" + (o.getIndex() + 1);
  				if (digits) {
  					// prepend leading zeroes
  					s = ("0000000" + s).substr(-digits);
  				}
  				res.push(s);
  			});
  			return res.join(separator);
  		}
docs: Return the hierarchical child index (1-based, e.g. '3.2.4').
  @param {string} [separator="."]
  @param {int} [digits=1]
  @returns {string}