def matrix_type(request):
    return request.param
def test_impl(n):
            df1 = pd.DataFrame({'key1': np.arange(n), 'A': np.arange(n) + 1.0})
            df2 = pd.DataFrame({'key2': n - np.arange(n), 'A': n + np.arange(n) + 1.0})
            df3 = pd.concat([df1, df2])
            return df3.A.sum() + df3.key2.sum()