I.5.2 Extraction functions

Two extraction functions have been defined:

• “extractLayers” returns an Array of String and integers corresponding to the layers that are referenced in the ResKeyList object.
• “extractSubLayers” returns an Array of String and integers corresponding to the sub-layers that are referenced in the ResKeyList object.
• “extractGroup” returns a Group object containing the elements and nodes that are referenced in the ResKeyList object.

These methods have no arguments.