def _getcached(cls, source):
        '''
        get an object from cache.
        if the object is not in cache or cache is disabled None will be returned.
        '''
        if hasattr(cls, '__proxy_cache__') and cls.__proxy_cache__ != None \
                and source in cls.__proxy_cache__:
            return cls.__proxy_cache__[source]
        return None

        get an object from cache.
        if the object is not in cache or cache is disabled None will be returned.
        
recipes/Python/305308_mixins_for_proxy_construction/recipe-305308.py