New Post: LayerKey for layers

MapWindow has this property called LayerKey that is used like so Map.LayerKey that can store some bit of info as the user sees fit. I load a description of the layer like so
Map.LayerKey(hnd) = shapeType & numShapes & calcTime

Later when a user hovers over the polyline I can show that info in a Tooltip. Does DotSpatial have a property that can hold a string of data like LayerKey?