): P? = parametersTypeOf(action)?.let { parametersType ->
        flowParametersInstantiator.newInstance(parametersType) { parameters ->
            val spec = specInstantiator.newInstance(DefaultFlowActionSpec::class.java, parameters)
            configure.execute(spec.uncheckedCast())
        }
    }

    private
    fun <P : FlowParameters, T : FlowAction<P>> parametersTypeOf(action: Class<T>): Class<P>? =