add Channel.join()

src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java

@@ -83,7 +83,7 @@ public abstract class AbstractChannel
     /** Channel open event */
     protected final Event<ConnectionException> open;
     /** Channel close event */
-    private final Event<ConnectionException> close;
+    protected final Event<ConnectionException> close;
 
     /* Access to these fields should be synchronized using this object */
     private boolean eofSent;
@@ -267,6 +267,11 @@ public abstract class AbstractChannel
         }
     }
 
+    public void join()
+            throws ConnectionException {
+        close.await();
+    }
+
     protected synchronized void sendClose()
             throws TransportException {
         try {

src/main/java/net/schmizz/sshj/connection/channel/Channel.java

@@ -135,4 +135,7 @@ public interface Channel
      */
     void setAutoExpand(boolean autoExpand);
 
+    void join()
+            throws ConnectionException;
+
 }