docs: def enqueue(self, priority: int, item: TItem) -> bool:
          """Adds an entry to the priority queue.
  
          If drop_duplicate_entries is set and there is already a (priority, item)
          entry in the queue, then the enqueue is ignored. Check the return value
          to determine if an enqueue was kept or dropped.
  
          Args:
              priority: The priority of the item. Lower priorities dequeue before
                  higher priorities.
              item: The item associated with the given priority.
  
          Returns:
              True if the item was enqueued. False if drop_duplicate_entries is
              set and the item is already in the queue.
          """
          if self._drop_set is not None:
              if (priority, item) in self._drop_set:
                  return False
              self._drop_set.add((priority, item))
  
          # First enqueue initializes self._offset.
          if not self._buckets:
              self._buckets.append([item])
              self._offset = priority
              self._len = 1
              return True
  
          # Where is the bucket this item is supposed to go into?
          i = priority - self._offset
  
          # Extend bucket list backwards if needed.
          if i < 0:
              self._buckets[:0] = [[] for _ in range(-i)]
              self._offset = priority
              i = 0
  
          # Extend bucket list forwards if needed.
          while i >= len(self._buckets):
              self._buckets.append([])
  
          # Finish by adding item to the intended bucket's list.
          self._buckets[i].append(item)
          self._len += 1
          return True