The unique identifying string for the layer, as specified in a map or scene. The id is used by other parts of this API to refer to a specific Layer, such as in a set of FeatureFenceParameters or a FacilityLayerDefinition. If not supplied, all layers will be assigned a unique id when created.
It is not recommended to change this property when the layer is obtained from a map or scene. If changed, ensure that the string is unique, for example based on a generated GUID.