function assertIsSubscriptionLikeimport { assertIsSubscriptionLike } from "https://deno.land/x/observable@v0.1-alpha/utils.ts"; assertIsSubscriptionLike(subscription: any, msg?: string): asserts subscription is SubscriptionLikeParameterssubscription: anyoptionalmsg: string = [UNSUPPORTED]Returnsasserts subscription is SubscriptionLike