public override Object InitializeLifetimeService()
{
    BCLDebug.Trace("REMOTE", "ObjectHandle.InitializeLifetimeService");

    //
    // If the wrapped object has implemented InitializeLifetimeService to return null,
    // we don't want to go to the base class (which will result in a lease being
    // requested from the MarshalByRefObject, which starts up the LeaseManager,
    // which starts up the ThreadPool, adding three threads to the process.
    // We check if the wrapped object is a MarshalByRef object, and call InitializeLifetimeServices on it
    // and if it returns null, we return null. Otherwise we fall back to the old behavior.
    //

    MarshalByRefObject mbr = WrappedObject as MarshalByRefObject;
    if (mbr != null) {
        Object o = mbr.InitializeLifetimeService();
        if (o == null)
            return null;
    }
    ILease lease = (ILease)base.InitializeLifetimeService();
    return lease;
}

public override object InitializeLifetimeService()
{
    var lease = base.InitializeLifetimeService() as ILease;
    lease?.Register(LifeTimeSponsor);
    return lease;
}