Function createFlattenedLayerXList

createFlattenedLayerXList(source): Collection<LayerExtension>
Flattens a MapExtension or a Collection of LayerExtensions into a single Collection of LayerExtensions, including nested group layers.
Parameters
- source: MapExtension | Collection<LayerExtension<LayerExtensionProperties>>
  The MapExtension or Collection of LayerExtensions to flatten.
Returns Collection<LayerExtension>
A flattened Collection of LayerExtensions.