ClassBuilder#build now only making one getMeta call

lib/ClassBuilder.js

@@ -326,12 +326,14 @@ exports.prototype.build = function extend( _, __ )
             props:   this._memberBuilder.initMembers(),
         },
 
+        meta = exports.getMeta( base ),
+
         abstract_methods =
-            util.clone( exports.getMeta( base ).abstractMethods )
+            util.clone( meta.abstractMethods )
             || { __length: 0 },
 
         virtual_members =
-            util.clone( exports.getMeta( base ).virtualMembers )
+            util.clone( meta.virtualMembers )
             || {}
     ;