docs: function (params) {
                  var n,
                      norm,
                      builder = this;
                  for (n in list) {
                      builder[n] = list[n];
                  }
                  for (n in params) {
                      if (params.hasOwnProperty(n)) {
                          norm = n[0].toUpperCase() + n.slice(1);
                          if (!list.hasOwnProperty(norm)) {
                              throw new Error('Invalid Zuora object ' + type + ' has no property: ' + norm);
                          }
                          builder[norm] = params[n];
                      }
                  }
              }