OptionalBackgroundTernaryFunction
class OptionalBackgroundTernaryFunction<A, OA : ObservableValue<A>, B, OB : ObservableValue<B>, C, OC : ObservableValue<C>>(argA: OA, argB: OB, argC: OC, lambda: (A, B, C) -> Background?) : TernaryFunction<Background?, A, OA, B, OB, C, OC> , ObservableOptionalBackground
Boilerplate which avoids having to use generics.
Similar to BackgroundTernaryFunction, but the value can also be null.