code: def test_expr2(self):
      instruments = ["sh600519"]
      fields = ["P($$roewa_q)", "P($$yoyni_q)"]
      fields += [
          "P(($$roewa_q / $$yoyni_q) / Ref($$roewa_q / $$yoyni_q, 1) - 1)"
      ]
      fields += ["P(Sum($$yoyni_q, 4))"]
      fields += ["$close", "P($$roewa_q) * $close"]
      data = D.features(
          instruments,
          fields,
          start_time="2019-01-01",
          end_time="2020-01-01",
          freq="day",
      )
      except_data = """
                                         P($$roewa_q)  P($$yoyni_q)  P(($$roewa_q / $$yoyni_q) / Ref($$roewa_q / $$yoyni_q, 1) - 1)  P(Sum($$yoyni_q, 4))      $close  P($$roewa_q) * $close
          instrument datetime
          sh600519   2019-01-02      0.255220      0.243892                                           1.484224                           1.661578   63.595333              16.230801
                     2019-01-03      0.255220      0.243892                                           1.484224                           1.661578   62.641907              15.987467
                     2019-01-04      0.255220      0.243892                                           1.484224                           1.661578   63.915985              16.312637
                     2019-01-07      0.255220      0.243892                                           1.484224                           1.661578   64.286530              16.407207
                     2019-01-08      0.255220      0.243892                                           1.484224                           1.661578   64.212196              16.388237
          ...                             ...           ...                                                ...                                ...         ...                    ...
                     2019-12-25      0.255819      0.219821                                           0.677052                           1.081693  122.150467              31.248409
                     2019-12-26      0.255819      0.219821                                           0.677052                           1.081693  122.301315              31.286999
                     2019-12-27      0.255819      0.219821                                           0.677052                           1.081693  125.307404              32.056015
                     2019-12-30      0.255819      0.219821                                           0.677052                           1.081693  127.763992              32.684456
                     2019-12-31      0.255819      0.219821                                           0.677052                           1.081693  127.462303              32.607277
  
          [244 rows x 6 columns]
          """
      self.check_same(data, except_data)
  
imports: import sys
  import qlib
  import shutil
  import unittest
  import pytest
  import pandas
  import baostock
  from pathlib import Path
  from qlib.data import D
  from qlib.tests.data import GetData
  from dump_pit import DumpPitData
  from collector import Run
label_desc: Use image node_id 10 for calling the TestPIT obj's underlying member method code with example usage: obj.test_expr2() without return types