SplitNode
if (SplitNode(node,nodeAndKey.nodeOffset,&nodeAndKey.keyIndex,keyBuffer,&keyLength,&valueToInsert) < B_OK) {
status_t SplitNode(bplustree_node *node, off_t nodeOffset, uint16 *_keyIndex, uint8 *key, uint16 *_keyLength, off_t *_value);