Don't add channels until fully initialized.

org.jdrupes.vmoperator.manager.events/src/org/jdrupes/vmoperator/manager/events/ChannelManager.java

@@ -62,6 +62,11 @@ public class ChannelManager<K, C extends Channel, A>
         this(k -> null);
     }
 
+    /**
+     * Return all keys.
+     *
+     * @return the keys.
+     */
     @Override
     public Set<K> keys() {
         return entries.keySet();
@@ -113,6 +118,18 @@ public class ChannelManager<K, C extends Channel, A>
         return this;
     }
 
+    /**
+     * Creates a new channel without adding it to the channel manager.
+     * After fully initializing the channel, it should be added to the 
+     * manager using {@link #put(K, C)}.
+     *
+     * @param key the key
+     * @return the c
+     */
+    public C createChannel(K key) {
+        return supplier.apply(key);
+    }
+
     /**
      * Returns the {@link Channel} for the given name, creating it using 
      * the supplier passed to the constructor if it doesn't exist yet.