IF_SWF_IFS_DECISION_EXIT how to get access the key fields into exit

Hi All,

I have implemented the above interface in workflow program exit say ZCL_DECISION_EXIT.

Followed the link to implement it  Dynamic user decisions in SAP Business Workflow.

lo_container = im_workitem_context->get_wf_container( ). Go the container instance into exit:ZCL_DECISION_EXIT

how to get the instance of BO: ZBUS2054 (supertype of BUS2054) from container into exit:ZCL_DECISION_EXIT to  access key fields “ZBUS2054.InternalItemNumber” . So that i can pull other data from DB based on InternalItemNumber

How to refere BO  as variable in the exit

Ex: lo_ZBUS2054 type ref to ZBUS2054. Is it correct

So that i can access the key fileds

lo_container->get( EXPORTING name = 'BUS2054'

                   IMPORTING value = lo_ZBUS2054).

Any aletnative way to get data into exit:ZCL_DECISION_EXIT please suggest me