code: function (collection, elements, settings, oldIndex, newIndex) {
              for (var i = oldIndex + 1; (i <= newIndex); i++) {
                  elements = swapElements(collection, elements, i, i - 1);
              }
              return collection.find(settings.elements_selector);
          }
docs: moving an element down of 3 rows means increasing its index of 3, and decreasing the 2 ones between of 1. Example: 0-A 1-B 2-C 3-D: moving B to 3 becomes 0-A 1-C 2-D 3-B