// use statement-wide agent-instance-specific subselects
AIRegistryExpr aiRegistryExpr = statementContext.getStatementAgentInstanceRegistry().getAgentInstanceExprService();
subselectStrategyInstances = new HashMap<ExprSubselectNode, SubSelectStrategyHolder>();
for (Map.Entry<ExprSubselectNode, SubSelectStrategyFactoryDesc> entry : selectDesc.getSubSelectStrategyCollection().getSubqueries().entrySet()) {
AIRegistrySubselect specificService = aiRegistryExpr.allocateSubselect(entry.getKey());
entry.getKey().setStrategy(specificService);
Map<ExprPriorNode, ExprPriorEvalStrategy> subselectPriorStrategies = new HashMap<ExprPriorNode, ExprPriorEvalStrategy>();
for (ExprPriorNode subselectPrior : entry.getValue().getPriorNodesList()) {
AIRegistryPrior specificSubselectPriorService = aiRegistryExpr.allocatePrior(subselectPrior);