code: def prepped_experiment(request):
      """Build a partially prepared :class:`~hyperparameter_hunter.experiments.CVExperiment` instance
  
      Specifically, automatic execution is disabled via `auto_start=False`, then the following methods
      are called:
  
      1. :meth:`~hyperparameter_hunter.experiments.BaseExperiment.preparation_workflow`,
      2. :meth:`~hyperparameter_hunter.experiments.BaseExperiment._initialize_random_seeds`, and
      3. :meth:`~hyperparameter_hunter.experiments.BaseExperiment.on_exp_start`, which initializes the
         four :mod:`~hyperparameter_hunter.data.datasets` classes, then performs pre-CV feature
         engineering
  
      Notes
      -----
      Directly calling `on_exp_start` is ok in this test because after calling
      `_initialize_random_seeds`, `BaseExperiment` calls `execute`, which is implemented by
      `BaseCVExperiment`, and only calls `cross_validation_workflow`, whose first task is to call
      `on_exp_start`. So nothing gets skipped in between"""
      #################### Build `feature_engineer` ####################
      feature_engineer = FeatureEngineer(steps=request.param)
  
      #################### Partially Prepare `CVExperiment` ####################
      experiment = CVExperiment(
          model_initializer=AdaBoostClassifier,
          model_init_params=dict(),
          feature_engineer=feature_engineer,
          auto_start=False,
      )
      experiment.preparation_workflow()
      # noinspection PyProtectedMember
      experiment._initialize_random_seeds()
      experiment.on_exp_start()
  
      return experiment
  
imports: from hyperparameter_hunter import Environment, CVExperiment, FeatureEngineer, EngineerStep
  from hyperparameter_hunter.callbacks.recipes import dataset_recorder
  import numpy
  from numpy.testing import assert_array_almost_equal
  import pandas
  from pandas.testing import assert_frame_equal
  import pytest
  from sklearn.ensemble import AdaBoostClassifier
  from sklearn.preprocessing import StandardScaler
label_desc: Use image node_id 14 for calling a global function with example usage: prepped_experiment(request) and returns: experiment