newSiblingNode->data = safe_malloc(tree->dataSize);
memcpy(newSiblingNode->data, data, tree->dataSize);
newSiblingNode->next = treeNode->next;
newSiblingNode->data = safe_malloc(tree->dataSize);
memcpy(newSiblingNode->data, data, tree->dataSize);
newSiblingNode->next = treeNode->next;