OptionalEdgesBinaryFunction
class OptionalEdgesBinaryFunction<A, OA : ObservableValue<A>, B, OB : ObservableValue<B>>(argA: OA, argB: OB, lambda: (A, B) -> Edges?) : BinaryFunction<Edges?, A, OA, B, OB> , ObservableOptionalEdges
Boilerplate which avoids having to use generics.
Similar to EdgesBinaryFunction, but the value can also be null.