function flatMapimport { flatMap } from "https://deno.land/x/async_channels@v1.0.0-alpha54/pipe.ts"; flatMap<T, TOut>(fn: (val: T) => Iterable<TOut> | AsyncIterable<TOut>, pipeOpts?: ChannelPipeOptions)Type ParametersTTOutParametersfn: (val: T) => Iterable<TOut> | AsyncIterable<TOut>optionalpipeOpts: ChannelPipeOptions