code: def from_engine_hovernet(
      keys: KeysCollection, nested_key: str
  ) -> Callable[[Any], Any]:
      """
      Since the output of HoVerNet is a dictionary, this function is to extend `monai.handlers.from_engine`
      to work with HoVerNet.
  
      If data is a list of nested dictionaries after decollating, extract nested value with expected keys and
      construct lists respectively, for example,
      if data is `[{"A": {"C": 1, "D": 2}, "B": {"C": 2, "D": 2}}, {"A":  {"C": 3, "D": 2}, "B":  {"C": 4, "D": 2}}]`,
      from_engine_hovernet(["A", "B"], "C"): `([1, 3], [2, 4])`.
  
      Here is a simple example::
  
          from monai.handlers import MeanDice, from_engine_hovernet
  
          metric = MeanDice(
              include_background=False,
              output_transform=from_engine_hovernet(keys=["pred", "label"], nested_key=HoVerNetBranch.NP.value)
          )
  
      Args:
          keys: specified keys to extract data from dictionary or decollated list of dictionaries.
          nested_key: specified key to extract nested data from dictionary or decollated list of dictionaries.
  
      """
      _keys: tuple[Hashable, ...] = ensure_tuple(keys)
  
      def _wrapper(data):
          if isinstance(data, dict):
              return tuple(data[k][nested_key] for k in _keys)
          if isinstance(data, list) and isinstance(data[0], dict):
              # if data is a list of dictionaries, extract expected keys and construct lists,
              ret = [[i[k][nested_key] for i in data] for k in _keys]
              return tuple(ret) if len(ret) > 1 else ret[0]
  
      return _wrapper
  
imports: from __future__ import annotations
  from collections.abc import Callable, Hashable
  from typing import Any
  from monai.config import KeysCollection
  from monai.utils import ensure_tuple
label_desc: Use image node_id 1 for calling a global function with example usage: from_engine_hovernet(keys, nested_key) and returns: _wrapper, tuple, unknown