docs: public void Draw( DrawingDecorator drawingNode, World world ) throws Exception
      {
          beginDrawing(world);
  
          for(JAXBElement<?> jaxbobj : drawingNode.getDrawObjectType())
          {
              Object obj = jaxbobj.getValue();
              // isn't there an easier way of doing this?
              if( obj instanceof DrawBlock )
                  DrawPrimitive( (DrawBlock)obj, world );
              else if( obj instanceof DrawItem )
                  DrawPrimitive( (DrawItem)obj, world );
              else if( obj instanceof DrawCuboid )
                  DrawPrimitive( (DrawCuboid)obj, world );
              else if (obj instanceof DrawSphere )
                  DrawPrimitive( (DrawSphere)obj, world );
              else if (obj instanceof DrawLine )
                  DrawPrimitive( (DrawLine)obj, world );
              else if (obj instanceof DrawEntity)
                  DrawPrimitive( (DrawEntity)obj, world );
              else if (obj instanceof DrawContainer)
                  DrawPrimitive( (DrawContainer)obj, world );
              else if (obj instanceof DrawSign)
                  DrawPrimitive( (DrawSign)obj, world );
              else
                  throw new Exception("Unsupported drawing primitive: "+obj.getClass().getName() );
          }
  
          endDrawing(world);
      }