Nullability in TrackGraph signature

[sjb-sjb]

A very very minor issue for cleanup whenever convenient.

The type of TrackGraph is

public virtual void TrackGraph<TState> (object rootEntity, TState? state,  Func<EntityEntryGraphNode<TState>,bool> callback);

The callback however should have the argument type annotated with ?,

Func<EntityEntryGraphNode<TState?>, bool> callback

so that the ability to pass null into TrackGraph will be matched by the ability of the callback to accept null as the state arg.

Workaround: specify TState? explicitly as the type argument to TrackGraph.

[roji]

I think we need to do the opposite, i.e. remove the question mark on the state parameter. Since this is an unconstrained generic parameter, you can pass any type to it (including nullable).