public void SameTooltipObjectForMultipleObjects_RemoveFromSecond () { // ToolTip does not set "ContentControl.ContentSetsParent" to false var data = new Rectangle (); var target1 = new Grid (); var target2 = new Grid (); ToolTipService.SetToolTip (target1, data); ToolTipService.SetToolTip (target2, data); target2.ClearValue (ToolTipService.ToolTipProperty); Assert.IsInstanceOfType<ToolTip> (data.Parent); }