LayoutFarm.Text.EditableTextFlowLayer.AddBefore C# (CSharp) Method

        public void AddBefore(EditableRun beforeVisualElement, EditableRun visualElement)
        {
            EditableTextLine targetLine = beforeVisualElement.OwnerEditableLine;
            if (targetLine != null)
            {
                targetLine.AddBefore(beforeVisualElement, visualElement);
            }
            else
            {
                throw new NotSupportedException();
            }
        }