function nextItem(itemElement, isPageScroll, forward)
        {
            var scrollItemsLeft = isPageScroll && this._rowsPerViewport ? this._rowsPerViewport : 1;
            var candidate = itemElement;
            var lastVisibleCandidate = candidate;
            do {
                candidate = forward ? candidate.nextSibling : candidate.previousSibling;
                if (!candidate) {
                    if (isPageScroll)
                        return lastVisibleCandidate;
                    else
                        candidate = forward ? this._itemElementsContainer.firstChild : this._itemElementsContainer.lastChild;
                }
                if (!this._itemElementVisible(candidate))
                    continue;
                lastVisibleCandidate = candidate;
                --scrollItemsLeft;
            } while (scrollItemsLeft && candidate !== this._selectedElement);

            return candidate;
        }
@param {string=} query
@param {boolean=} isGlobal