typedef struct FileSystemTree <> impl FTree {
  struct Node* root;
  struct Node* current; // reading node of original tree;
  struct Node* previous; // parent of reading node of original tree;
  struct Node* newNode; // writing node of new tree;
  struct Node* parent;
  struct Node* grandparent;
  struct Stack* nodeStack;
  __code findNodeNext(...);
  int result;
  int inum;
} FileSystemTree;