code: def setUp(self) -> None:
      freq = "day"
      expressions = [
          "$change",
          "Abs($change)",
      ]
      columns = ["change", "abs"]
      self.data = DatasetProvider.inst_calculator(
          self.inst,
          self.start_time,
          self.end_time,
          freq,
          expressions,
          self.spans,
          C,
          [],
      )
      self.data.columns = columns
  
file_path: qlib/tests/ops/test_elem_operator.py
imports: import unittest
  import numpy
  import pytest
  from qlib.data import DatasetProvider
  from qlib.data.data import ExpressionD
  from qlib.tests import TestOperatorData, TestMockData, MOCK_DF
  from qlib.config import C
label_desc: Use image node_id 1 for calling the TestInstElementOperator obj's underlying member method code with example usage: obj.setUp() without return types