code: def init_app(self, app):
          
          # If app is a blueprint, defer the initialization
          try:
              app.record(self._deferred_blueprint_init)
          # Flask.Blueprint has a 'record' attribute, Flask.Api does not
          except AttributeError:
              self._init_app(app)
          else:
              self.blueprint = app
docs: Initialize this class with the given :class:`flask.Flask`
          application or :class:`flask.Blueprint` object.
  
          :param app: the Flask application or blueprint object
          :type app: flask.Flask
          :type app: flask.Blueprint
  
          Examples::
  
              api = Api()
              api.add_resource(...)
              api.init_app(app)