Value node data can not be get from Get_ Method

Hi All expert,

I create valued node with

   CREATE OBJECT lr_mixed EXPORTING iv_model_node = lr_btadmini iv_struct = ls_data.

Then added it to context with

    lr_col->if_bol_bo_col~add( lr_mixed ).

    lr_cuco->typed_context->btadmini->collection_wrapper->set_collection( lr_col ).

But in every get_ method for the value node could not get data from the value node.it seems it get another value node instance which has not data.

Anyone know the where is the problem and how to fix it?

tks in advance.