code: def suite():
      _suite = unittest.TestSuite()
      _suite.addTest(TestAllFlow("test_0_train"))
      _suite.addTest(TestAllFlow("test_1_backtest"))
      _suite.addTest(TestAllFlow("test_2_expmanager"))
      return _suite
  
imports: import sys
  import shutil
  import unittest
  import pytest
  from pathlib import Path
  import qlib
  from qlib.config import C
  from qlib.utils import init_instance_by_config, flatten_dict
  from qlib.workflow import R
  from qlib.workflow.record_temp import SignalRecord, SigAnaRecord, PortAnaRecord
  from qlib.tests import TestAutoData
  from qlib.tests.config import CSI300_GBDT_TASK, CSI300_BENCH
label_desc: Use image node_id 4 for calling a global function with example usage: suite() and returns: _suite