code: def test_diff_inv(arr, lag, differences, xi, expected):
      res = diff_inv(arr, lag=lag, differences=differences, xi=xi)
      expected = np.array(expected, dtype=float)
      assert_array_equal(expected, res)
  
imports: from pmdarima.utils.array import diff, diff_inv, c, is_iterable, as_series, check_exog, check_endog
  from pmdarima.utils import get_callable
  from numpy.testing import assert_array_equal, assert_array_almost_equal
  import datetime
  import pytest
  import pandas
  import numpy
label_desc: Use image node_id 3 for calling a global function with example usage: test_diff_inv(arr, lag, differences, xi, expected) without return types