def get_jinja2(factory=Jinja2, key=_registry_key, app=None):
 app = (app or webapp2.get_app())
 jinja2 = app.registry.get(key)
 if (not jinja2):
  jinja2 = app.registry[key] = factory(app)
 return jinja2

def get_jinja2 ( factory = Jinja2 , key = _registry_key , app = None ) : app = ( app or webapp2 . get_app ( ) ) jinja2 = app . registry . get ( key ) if ( not jinja2 ) : jinja2 = app . registry [ key ] = factory ( app ) return jinja2
returns an instance of :class:jinja2 from the app registry .