In the 2.x API, I was able to set the map selection via the below code.
MapView.Active.Map.SetSelection(new Dictionary<MapMember, List<long>> { { bFl, oidList } });
in 3.0, this code errors out, but the intellisense says that the SetSelection method takes a SelectionSet object as a parameter.

However, I cannot figure out how to instantiate a SelectionSet object. There is no useful information in the API reference for SelectionSet, and the only snippet for the .SetSelection() method is how to clear the selection with .SetSelection(null).
So I am at a loss. How does one programatically select features on the map with the new 3.0 API, given a BasicFeatureLayer object and a list of objectIDs?