ocus();
          selection.modify(
            "move",
            testData.direction,
            testData.granularity
          );
          // After modification, the selection should should have collapsed and should be on the endNode of the test with offset same as the initial focus offset
          assert_true(selection.isCollapsed);
          assert_equals(selection.focusOffset, testData.focusOffset);
          assert_equals(selection.focusNode, testData.endNode);
        }, testData.description);
  