code: def register(self):
          
          if self.app is not None:
              if not self.blueprint:
                  self.blueprint = self.create_blueprint()
              self.app.register_blueprint(self.blueprint)
              if self.cache is None:
                  # We register a fake cache extension.
                  setattr(self.app.jinja_env, "_fake_cache_extension", self)
                  self.app.jinja_env.add_extension(FakeCacheExtension)
              return self.blueprint
          return None
docs: Register the app using Blueprint
  
          :return: Nemo blueprint
          :rtype: flask.Blueprint