entRect().height, 1 * emToPx, epsilon, "horizontal characters don't stretch vertically");

          element = document.getElementById("vertical_arrow");
          assert_approx_equals(element.getBoundingClientRect().height, 6 * emToPx, epsilon, "vertical characters stretch vertically");
      }, `Taking into account stretch axis.`);

      test(function() {
          element = document.getElementById("non_stretchy_horizontal_arrow");
          assert_approx_equals(element.getBoundingClientRect().height, 1 