A ModelExtensionAssistant pertains to one specific namespace yet has methods that have parameters that take a namespace or have methods that return data gathered with knowledge of other namespaces. This abstract class API should be changed to remove methods like this. For instance, the "supports(Object, String)" method takes a namespace prefix as the second parameter. This second parameter should be deleted as an assistant knows its own namespace prefix. Also the method "getSupportedNamespaces(Object)" should be deleted. An assistant should only be responsible for knowing if its own namespace is supported by a model object. All methods in the API should be checked for similar issues. And all subclasses should be checked to make sure similar issues aren't present.