public TemplateShapeContent([NotNull] IShapeCreator shapeCreator)
        {
            InitializeComponent();

            ShapeCreator = shapeCreator;
            Template     = shapeCreator.CreateTemplate(ShapeCreator, ItemUri.Empty);
        }
        public TemplateShapeContent([NotNull] IShapeCreator shapeCreator, [NotNull] ItemUri templateUri, [NotNull] string header)
        {
            Assert.ArgumentNotNull(shapeCreator, nameof(shapeCreator));
            Assert.ArgumentNotNull(templateUri, nameof(templateUri));
            Assert.ArgumentNotNull(header, nameof(header));

            InitializeComponent();

            ShapeCreator = shapeCreator;
            Header       = header;
            Template     = shapeCreator.CreateTemplate(ShapeCreator, templateUri);

            Loaded += ControlLoaded;
        }