Determines whether the layer record object is in-use when the generateUsageData() method is called and returns True if the layer is in-use, or False if the layer is not use.

Returns true when the generateUsageData() of the layer table object has not been called or this layer record object is not database resident.

Example of Working with the Layer Record Object 

Status of Layers 

OdDbLayerTable::generateUsageData() method