From f4bd3df39d775ef8f2e6fb9968a1a4dbceb90f8f Mon Sep 17 00:00:00 2001
From: Ben Christensen <benjchristensen@netflix.com>
Date: Mon, 9 Sep 2013 17:26:49 -0700
Subject: [PATCH] Generic covariance of concat.

See https://github.com/Netflix/RxJava/issues/360#issuecomment-24125591
---
 rxjava-core/src/main/java/rx/Observable.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rxjava-core/src/main/java/rx/Observable.java b/rxjava-core/src/main/java/rx/Observable.java
index 0ad73f45d08..ab84150a2f6 100644
--- a/rxjava-core/src/main/java/rx/Observable.java
+++ b/rxjava-core/src/main/java/rx/Observable.java
@@ -1199,7 +1199,7 @@ public static <T> Observable<T> merge(Observable<? extends T> t1, Observable<? e
      *         the {@code source} Observables, one after the other
      * @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
      */
-    public static <T> Observable<T> concat(Observable<Observable<T>> observables) {
+    public static <T> Observable<T> concat(Observable<? extends Observable<? extends T>> observables) {
         return create(OperationConcat.concat(observables));
     }