161     const Cell *old_cell = FindCell(key);  in Add()
166     Cell *new_cell = new Cell(key, value, head_);  in Add()
174     const Cell *cell = FindCell(key);  in Lookup()
190     for (const Cell *c = head_; c!= nullptr; c = c->next()) {  in GetComponentNames()
199   class Cell {
202     Cell(const char *key, T *value, Cell *next)  in Cell()  function
207     Cell *next() const { return next_; }  in next()
212     Cell *const next_;
220   const Cell *FindCell(const char *key) const {  in FindCell()
221     const Cell *c = head_;  in FindCell()
232   Cell *head_;