Changing options when rendering twice datagrid

Hello I am still studying the CVS version of Datagrid and I'm a bit confused about initialisation of renderers and options. Is there a clear definition of what Structures_DataGrid_Renderer::init() is expected to do? Especially, if we change some options, what is the expected behaviour? I am not fully sure, but if I run the following code, the renderer will output twice the same data: $datagrid->render(null, array('foo'=>'1'); $datagrid->render(null, array('foo'=>'2'); -- Michel