# File test/test_sexp.rb, line 264
  def test_structure
    @sexp    = s(:a, 1, 2, s(:b, 3, 4), 5, 6)
    backup = @sexp.deep_clone
    expected = s(:a, s(:b))

    assert_equal(expected, @sexp.structure)
    assert_equal(backup, @sexp)
  end