private Accumulator<FrameNode, IEnumerable<Guid>> GetAccumulator(Relation relation,Query query)
{
var factory = new AccumulatorFactory();
var plan = new FramingPlan(relation.ParentElement);
var acc = factory.GetOrCreateAccumulator(plan,
(keys, parPairs) =>
query.GetMultipleChildResourceQuery(relation.ParentElement.Name,parPairs.Select(k=>k.Key).ToArray())(keys,parPairs.Select(k=>k.Value).ToArray()),
relation.ParentElement, relation.ChildElement, new ParameterNames());
return acc;
}
