pe: "mouseover",  target: '<div id="div5">', buttons: 1, button: 0 },
          { type: "mouseenter", target: '<div id="div5">', buttons: 1, button: 0 },
        ]),
        "Mouse boundary events should have the state of primary button pressed"
      );
    });
    assert_equals(
      stringifyEvents(pointerEvents),
      stringifyEvents([
        { type: "pointerout",   target: '<div id="div0">', buttons: 1, button: -1, pointerId, pointerType: "mouse" },
        { type: "pointerleave", target: '<div id="