code: def test_prev_cache_parallel_deletion():
      # all files cache files in test dir must be removed
      # if `cache_dir` api param wasn't specified explicitly
      unused_test_pid = get_unused_pid()
      test_file_1 = Path(
          default_fedot_data_dir(),
          f"cache_{unused_test_pid}.operations_db",
      )
      test_file_1.touch()
      test_file_2 = Path(
          default_fedot_data_dir(),
          f"cache_{unused_test_pid}.preprocessors_db",
      )
      test_file_2.touch()
  
      common_params = dict(timeout=0.1, with_tuning=False)
  
      tasks = [
          delayed(run_regression_example)(
              **common_params, preset="fast_train"
          ),
          delayed(run_classification_example)(**common_params),
          delayed(run_ts_forecasting_example)(
              **common_params, dataset="beer", horizon=10
          ),
      ]
  
      cpus = cpu_count()
      if cpus > 1:
          try:
              Parallel(n_jobs=cpus)(tasks)
          except sqlite3.OperationalError:
              assert False, "DBs collides"
          assert not test_file_1.exists()
          assert not test_file_2.exists()
  
file_path: FEDOT/test/integration/cache/test_cache_parallel.py
imports: import sqlite3
  from pathlib import Path
  import psutil
  from joblib import Parallel, cpu_count, delayed
  from examples.simple.classification.api_classification import run_classification_example
  from examples.simple.regression.api_regression import run_regression_example
  from examples.simple.time_series_forecasting.api_forecasting import run_ts_forecasting_example
  from fedot.core.utils import default_fedot_data_dir
label_desc: Use image node_id 2 for calling a global function with example usage: test_prev_cache_parallel_deletion() without return types