code: function subSteps (obj, items) {
      util.inherits(obj, Ctx);
  
      var key = "teamcontacts versions successors predecessors".split(" ")
      ,   propKey = "team-contacts version-history successor-version predecessor-version".split(" ");
      items.forEach(function (it) {
          obj.prototype[it] = function () {
              this.steps.push(it);
              this.type = "list";
              var i = key.indexOf(it);
              this.linkKey = (i >= 0) ? propKey[i] : it;
              return this;
          };
      });
  }
docs: generates steps beneath an existing one that has an ID