flow like the river

BACK_BACK/node_modules/graphql/subscription/mapAsyncIterator.d.ts

@@ -0,0 +1,11 @@
+import { PromiseOrValue } from '../jsutils/PromiseOrValue';
+
+/**
+ * Given an AsyncIterable and a callback function, return an AsyncIterator
+ * which produces values mapped via calling the callback function.
+ */
+export default function mapAsyncIterator<T, U>(
+  iterable: AsyncIterable<T>,
+  callback: (arg: T) => PromiseOrValue<U>,
+  rejectCallback?: (arg: any) => PromiseOrValue<U>,
+): any; // TS_SPECIFIC: AsyncGenerator requires typescript@3.6