code: def test_is_iterable():
      assert not is_iterable("this string")
      assert is_iterable(["this", "list"])
      assert not is_iterable(None)
      assert is_iterable(np.array([1, 2]))
  
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 8 for calling a global function with example usage: test_is_iterable() without return types