- element1: parent.contents()[myIdx + (moveLeftRange ? -1 : 0)],
- element2: parent.contents()[myIdx + childrenLength-1 + (moveRightRange ? 1 : 0)]
+ element1: parent.contents()[myIdx + (shiftRange ? -1 : 0)],
+ element2: parent.contents()[myIdx + childrenLength-1 + (shiftRange ? -1 : 0)]