Behavior >> superclass: it's ok to just return JS null

src/Kernel-Classes.js

@@ -1388,7 +1388,7 @@ var self=this;
 //>>excludeStart("ctx", pragmas.excludeDebugContexts);
 return $core.withContext(function($ctx1) {
 //>>excludeEnd("ctx");
-return self.superclass || nil;
+return self.superclass;
 return self;
 //>>excludeStart("ctx", pragmas.excludeDebugContexts);
 }, function($ctx1) {$ctx1.fill(self,"superclass",{},$globals.Behavior)});
@@ -1396,7 +1396,7 @@ return self;
 },
 //>>excludeStart("ide", pragmas.excludeIdeData);
 args: [],
-source: "superclass\x0a\x09<return self.superclass || nil>",
+source: "superclass\x0a\x09<return self.superclass>",
 referencedClasses: [],
 //>>excludeEnd("ide");
 messageSends: []

src/Kernel-Classes.st

@@ -199,7 +199,7 @@ subclasses
 !
 
 superclass
-	<return self.superclass || nil>
+	<return self.superclass>
 !
 
 theMetaClass