final List<Set<ValueSpecification>> valuesBySnapshot = _valueMap.getUnderlyingSpecifications(values);
for (int i = 0; i < _snapshots.size(); i++) {
final MarketDataSnapshot snapshot = _snapshots.get(i);
final Set<ValueSpecification> snapshotSubscriptions = valuesBySnapshot.get(i);
if (!snapshotSubscriptions.isEmpty()) {
final Map<ValueSpecification, Object> snapshotResults = snapshot.query(snapshotSubscriptions);
for (final Map.Entry<ValueSpecification, Object> snapshotResult : snapshotResults.entrySet()) {
results.put(_valueMap.convertUnderlyingSpecification(i, snapshotResult.getKey()), snapshotResult.getValue());
}
}
}