stream: allow pass stream class to stream.compose

Author: himself65

lib/internal/streams/duplexify.js

@@ -84,6 +84,9 @@ module.exports = function duplexify(body, name) {
 
   if (typeof body === 'function') {
     const { value, write, final, destroy } = fromAsyncGen(body);
+    if (isDuplexNodeStream(value)) {
+      return value;
+    }
 
     if (isIterable(value)) {
       return from(Duplexify, value, {