[cmd("insert_custom_entity")]
private void InsertCustomEntity()
{
    var cadView = this.CadView;
    if (DrawingLayer.GetDrawingLayer(cadView) is DrawingLayer drawingLayer)
    {
        var drawing = drawingLayer.Drawing;
        Vector3D point;
        if (!CadCursors.GetPoint(cadView, out point, "Укажите точку вставки примитива")) return;
        if (ImObjectPropertyProvider.SelectObject(CustomDwgEntity.PARENT_SMDX) is ImElement imElement)
        {
            var block = drawing.ActiveSpace;
            var entity = new CustomDwgEntity{Element = imElement, Position = point};
            block.Add(entity);

            cadView.Unlock();
            cadView.Invalidate();
        }
    }
}