| Associates a FeatureIndex with a query.
This is used to get a view from the index,
ie. a subset of the features containes in the index.
If more features are added to the underlying FeatureIndex,
after instance is created, instance will reflect new set,
as it delegates actual process to the FeatureIndex.
author: Christophe Rousson, SoC 2007, CRG-ULAVAL |