604     head: NodePtr<K, V>,  field
625         if self.head.is_null() {  in next()
629         let next = self.head.next();  in next()
632                 core::ptr::read(&(*self.head.0).key),  in next()
633                 core::ptr::read(&(*self.head.0).value),  in next()
636         self.head = next;  in next()
683     head: NodePtr<K, V>,  field
692             head: self.head,  in clone()
708         if self.head.is_null() {  in next()
712         let (k, v) = unsafe { (&(*self.head.0).key, &(*self.head.0).value) };  in next()
713         self.head = self.head.next();  in next()
731         if self.tail == self.head {  in next_back()
759     head: NodePtr<K, V>,  field
768             head: self.head,  in clone()
784         if self.head.is_null() {  in next()
788         let (k, v) = unsafe { (&(*self.head.0).key, &mut (*self.head.0).value) };  in next()
789         self.head = self.head.next();  in next()
806         if self.tail == self.head {  in next_back()
825                 head: NodePtr::null(),  in into_iter()
831                 head: self.first_child(),  in into_iter()
1400             head: self.first_child(),  in iter()
1411             head: self.first_child(),  in iter_mut()