Destroys this collection, all contained layers are detached from their parent group layer
Returns the items in this collection.
Optionaloptions: LayerRetrievalOptionsReturns all layers in this collection
Optionaloptions: LayerRetrievalOptionsReturns a list of all layers in the collection, including all children (recursively).
Note: This includes base layers by default (see
options.filter). Use the"base"or"operational"short hand values to filter by base layer or operational layers.If the group contains many, deeply nested sub groups, this function could potentially be expensive.
Optionaloptions: RecursiveRetrievalOptions
Contains Layer instances that belong to a GroupLayer