code: def test_rolling_forward_cov_corr(func, expected):
      values1 = np.arange(10).reshape(-1, 1)
      values2 = values1 * 2
      values1[5, 0] = 100
      values = np.concatenate([values1, values2], axis=1)
  
      indexer = FixedForwardWindowIndexer(window_size=3)
      rolling = DataFrame(values).rolling(window=indexer, min_periods=3)
      # We are interested in checking only pairwise covariance / correlation
      result = getattr(rolling, func)().loc[(slice(None), 1), 0]
      result = result.reset_index(drop=True)
      expected = Series(expected).reset_index(drop=True)
      expected.name = result.name
      tm.assert_equal(result, expected)
  
imports: import numpy
  import pytest
  from pandas import DataFrame, MultiIndex, Series, concat, date_range
  import pandas._testing
  from pandas.api.indexers import BaseIndexer, FixedForwardWindowIndexer
  from pandas.core.indexers.objects import ExpandingIndexer, FixedWindowIndexer, VariableOffsetWindowIndexer
  from pandas.tseries.offsets import BusinessDay
label_desc: Use image node_id 7 for calling a global function with example usage: test_rolling_forward_cov_corr(func, expected) without return types