-    registerExtension: function(extension) {
-        //debugger;
-        var doc = this,
-            existingPropertyName = _.values(this);
-
-        [
-            {source: extension.document, target: doc},
-            {source: extension.documentNode, target: [doc.ElementNodeFactory.prototype, doc.TextNodeFactory.prototype]},
-
-        ].forEach(function(x) {
-            if(x.source && x.source.methods) {
-                existingPropertyName = _.values(x.target)
-                _.pairs(x.source.methods).forEach(function(pair) {
-                    var methodName = pair[0],
-                        method = pair[1],
-                        targets = _.isArray(x.target) ? x.target : [x.target];
-                    if(_.contains(existingPropertyName, methodName)) {
-                        throw new Error('Cannot extend XXX with method name {methodName}. Name already exists.'.replace('{methodName}', methodName));
-                    }
-                    targets.forEach(function(target) {
-                        target[methodName] = method;
-                    });
-                    
-                });   
-            }
-        });
-
+    registerClassTransformation: function(Transformation, className) {
+        var thisClassTransformations = (this.classTransformations[className] = this.classTransformations[className] || new transformations.TransformationStorage());
+        return thisClassTransformations.register(Transformation);
+    },