code: def heappushpop(heap, item):
      """Fast version of a heappush followed by a heappop."""
      if heap and heap[0] < item:
          item, heap[0] = heap[0], item
          _siftup(heap, 0)
      return item
  
file_path: cpython/Lib/heapq.py
label_desc: Use image node_id 4 for calling a global function with example usage: heappushpop(heap, item) and returns: item