// if object source is null, then we need to adapt tuple source into a subnetwork
if ( context.getObjectSource() == null ) {
// attach right input adapter node to convert tuple source into an object source
context.setObjectSource( (ObjectSource) utils.attachNode( context,
new RightInputAdapterNode( context.getNextId(),
context.getTupleSource(),
context ) ) );
// restore tuple source from before the start of the sub network
context.setTupleSource( tupleSource );