Detect programmer error in delegate usage as early as possible and fail.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5223 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/crowd/server/PlaceManager.java

@@ -198,6 +198,7 @@ public class PlaceManager
      */
     public void addDelegate (PlaceManagerDelegate delegate)
     {
+        ratifyDelegate(delegate);
         if (_delegates == null) {
             _delegates = Lists.newArrayList();
         }
@@ -675,6 +676,14 @@ public class PlaceManager
         return 5 * 60 * 1000L;
     }
 
+    /**
+     * Protects against programmer error.
+     */
+    protected void ratifyDelegate (PlaceManagerDelegate delegate)
+    {
+        // nothing to do here, all PlaceManagerDelegates are safe for us
+    }
+
     /**
      * An extensible way to add to the string representation of this class. Override this (being
      * sure to call super) and append your info to the buffer.