{
Node xv = eval( item, X ), pv = eval( item, P );
Node dv = D == null ? null : eval( item, D );
if (dv == null)
{
throw new JenaException( "OOPS, we didn't do MakeInstance with no specified class" );
}
else
{
Object key = Pair.create( xv, Pair.create( pv, dv ) );
Node already = bnodes.get( key );