This method is used to instantiate a GML Abstract CRS
addComponentReferenceSystem(referenceSystem)
Adds a reference system
delComponentReferenceSystem(referenceSystem)
Deletes a reference system
References
ISO 19136:2007 Geographic Information -- Geographic Markup Language.
http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=32554