whole_func_string: function updateState() {
    history.replaceState(
      {
        left_top: split_left.scrollTop,
        right_top: split_right.scrollTop
      },
      document.title
    );
  }
func_code_string: function updateState() {
    history.replaceState(
      {
        left_top: split_left.scrollTop,
        right_top: split_right.scrollTop
      },
      document.title
    );
  }
func_documentation_string: Chrome doesn't remember scroll position properly so do it ourselves. Also works on Firefox and Edge.