Hi,
This is because, in the runtime environment you first did not load its respective component set.
Before your get_instance method -
lo_bol_core = cl_crm_bol_core=>get_instance( ).
lo_bol_core->load_component_set( component set name ).
lo_bol_core->start_up( 'component set name' ).
Once you do this, your desired query object can be picked up from this list.
Regards,
Vidya.