text: """Test mod for radix sort."""
  
  from radix_sort import radix_sort
  from random import randint
  import pytest
  
  
  def test_insertion():
      """Test with random list."""
      unsorted = [randint(0, 1000000) for i in range(1000)]
      assert radix_sort(unsorted) == sorted(unsorted)
  
  
  def test_radix_sort_worse_case():
      """Test with reversed list."""
      reverse = [i for i in range(1000)]
      reverse.reverse()
      assert radix_sort(reverse) == sorted(reverse)
  
  
  def test_radix_sort_passed_a_string():
      """Test that raises error."""
      with pytest.raises(TypeError):
          assert radix_sort('hello')
  
  
  def test_radix_sort_empty_list():
      """Test that properly handles an empty list."""
      assert radix_sort([]) == []
  
  
  def test_radix_sort_in_order():
      """Test doesn't mess with my list when in order."""
      in_order = [i for i in range(1000)]
      assert radix_sort(in_order) == in_order
  