message: make group transducer generic
diff: @@ -114,8 +114,8 @@ describe("Stream", () => {
  )
  }
  - function group(size: number) {
  - return Channel.transducer((input: O.Option<string>, state = L.empty<string>()) =>
  + function group<A>(size: number) {
  + return Channel.transducer((input: O.Option<A>, state = L.empty<A>()) =>
  Channel.gen(function* (_) {
  if (O.isSome(input)) {
  const newState = L.append_(state, input.value)
  