// Create keys (that exclude the temporal date/time information) from the interval
// and the data in the column discriminators.
final AggregationInterval interval = form.getInterval();
final HashSet<TabRenderAggregationKey> keys = new HashSet<TabRenderAggregationKey>();
for (TabRenderAggregationDiscriminator discriminator : columnDiscriminators) {
keys.add(new TabRenderAggregationKeyImpl(interval, discriminator.getAggregatedGroup(),
discriminator.getTabMapping()));
}
return keys;
}