code: def test_pad_ends():
      from speechbrain.lm.counting import pad_ends
  
      assert next(pad_ends(["a", "b", "c"])) == "<s>"
      assert next(pad_ends(["a", "b", "c"], pad_left=False)) == "a"
      assert (
          list(pad_ends(["a", "b", "c"], pad_left=False))[-1] == "</s>"
      )
      assert list(pad_ends([], pad_left=False))
      assert list(pad_ends([], pad_left=True))
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_pad_ends() without return types