public void rotate(int distance) {
    	rotate(0, size(), distance);
    }
Rotate specified elements in the list.
The distance argument can be positive or negative:
If it is positive, the elements are moved towards the end,
if negative, the elements are moved toward the beginning,
if distance is 0, the list is not changed.

@param distance	distance to move the elements
jphp-runtime/src/php/runtime/memory/support/IList.java