code: def getChildWithDefault(self, path, request):
          
          cached_resource = self.getCachedResource(request)
          if cached_resource:
              reactor.callInThread(
                  responseInColor,
                  request,
                  '200 OK',
                  cached_resource,
                  'Cached',
                  'underscore'
              )
              return cached_resource
          # original logic
          if path in self.children:
              return self.children[path]
          return self.getChild(path, request)
docs: Retrieve a static or dynamically generated child resource from me.