NXP-14879: Remove code duplication on descriptor since xmap can be extended now
NXP-14879: Add an aggregates definition into page provider descriptor
NXP-14879: Add getAggregates API and abstract impl
NXP-14879: improve API
NXP-14879: Use Lists instead of Arrays
NXP-14879: clean
NXP-14879: Add a way to set selection
NXP-14879: clean
NXP-14879: getSelection should never return null