code: def peek(self):
          
          # Ammortized O(1)
          _heap = self._heap
          _dict = self._dict
          val, key = _heap[0]
          # Remove items marked for lazy deletion as they are encountered
          while key not in _dict or _dict[key] != val:
              self._heappop(_heap)
              val, key = _heap[0]
          return key, val
docs: Peek at the next item in the queue