code: function (q) {
              var self = this;
              return this.find(q).chain(function (res) {
                  return res || self.create(q);
              });
          }
docs: Finds a single model according to the supplied filter.
  See {@link patio.Dataset#filter} for filter options. If the model
  does not exist then a new one is created as passed back.
  @param q