The Bio::DB::SeqFeature object is the default SeqFeature class stored in
 Bio::DB::SeqFeature databases. It implements both the
 Bio::DB::SeqFeature::NormalizedFeatureI and
 Bio::DB::SeqFeature::NormalizedTableFeatureI interfaces, which means that its
 subfeatures, if any, are stored in the database in a normalized fashion, and
 that the parent/child hierarchy of features and subfeatures are also stored
 in the database as set of tuples. This provides efficiencies in both storage
 and retrieval speed.
 .
 Typically you will not create Bio::DB::SeqFeature directly, but will ask the
 database to do so on your behalf, as described in Bio::DB::SeqFeature::Store.