code: def test_backtest_copies_strategy():
      s = mock.MagicMock()
      data = pd.DataFrame(
          index=pd.date_range("2010-01-01", periods=5),
          columns=["a", "b"],
          data=100,
      )
  
      actual = bt.Backtest(s, data, progress_bar=False)
  
      assert id(s) != id(actual.strategy)
  
file_path: bt/tests/test_backtest.py
imports: from __future__ import division
  import numpy
  import pandas
  import pytest
  import random
  from unittest import mock
  import bt
label_desc: Use image node_id 1 for calling a global function with example usage: test_backtest_copies_strategy() without return types