Returns an OutletT that gives access to the materialized value of this graph. Once the graph is materialized this outlet will emit exactly one element which is the materialized value. It is possible to expose this outlet as an externally accessible outlet of a SourceTOut, TMat, SinkTIn, TMat, FlowTIn, TOut, TMat or BidiFlowTIn1, TOut1, TIn2, TOut2, TMat. It is possible to call this method multiple times to get multiple OutletT instances if necessary. All of the outlets will emit the materialized value. Be careful to not to feed the result of this outlet to a stage that produces the materialized value itself (for example to a AggregateTIn, TOut(TOut, FuncTOut, TIn, TOut) that contributes to the materialized value) since that might lead to an unresolvable dependency cycle.

TBD