_SearchRightMost
error = _SearchRightMost(fCurrentNode->ToInternalNode(), k, &index);
error = _SearchRightMost(node, k, &fIndex);
status_t _SearchRightMost(InternalNode *node, const VKey *k, int32 *index);
status_t _SearchRightMost(LeafNode *node, const VKey *k,