code: def test_early_stopping() -> None:
      instrum = ng.p.Instrumentation(
          None, 2.0, blublu="blublu", array=ng.p.Array(shape=(3, 2))
      )
      func = _EarlyStoppingTestee()
      optimizer = optimizerlib.OnePlusOne(
          parametrization=instrum, budget=100
      )
      early_stopping = ng.callbacks.EarlyStopping(
          lambda opt: opt.num_ask > 3
      )
      optimizer.register_callback("ask", early_stopping)
      optimizer.register_callback(
          "ask", ng.callbacks.EarlyStopping.timer(100)
      )  # should not get triggered
      optimizer.minimize(func, verbosity=2)
      # num_ask is set at the end of ask, so the callback sees the old value.
      assert func.num_calls == 4
      # below functions are included in the docstring of EarlyStopping
      assert optimizer.current_bests["minimum"].mean < 12
      assert optimizer.recommend().loss < 12  # type: ignore
  
      # test for no improvement
      func = _EarlyStoppingTestee(5)
      optimizer = optimizerlib.OnePlusOne(
          parametrization=instrum, budget=100
      )
      no_imp_window = 7
      optimizer.register_callback(
          "ask",
          ng.callbacks.EarlyStopping.no_improvement_stopper(
              no_imp_window
          ),
      )  # should get triggered
      optimizer.minimize(func, verbosity=2)
      assert func.num_calls == no_imp_window + 2
  
      # test for no improvement multi objective
      func = _EarlyStoppingTestee(5, multi=True)
      optimizer = optimizerlib.OnePlusOne(
          parametrization=instrum, budget=100
      )
      no_imp_window = 5
      optimizer.register_callback(
          "ask",
          ng.callbacks.EarlyStopping.no_improvement_stopper(
              no_imp_window
          ),
      )  # should get triggered
      optimizer.minimize(func, verbosity=2)
      assert func.num_calls == no_imp_window + 2
  
imports: import time
  from pathlib import Path
  import logging
  import os
  import numpy
  import nevergrad
  import nevergrad.common.typing
  from .None import optimizerlib
  from .None import callbacks
label_desc: Use image node_id 7 for calling a global function with example usage: test_early_stopping() without return types