How to use the apollo-client.IntrospectionFragmentMatcher function in apollo-client

// To debug queries add print(req.request.query) and import it from graphql/language/printer
        // console.log(print(req.request.query));
        next();
      },
    },
  ]);

  const networkInterfaceWithSubscriptions = addGraphQLSubscriptions(
    networkInterface,
    wsClient
  );

  const client = new ApolloClient({
    connectToDevTools: true,
    addTypename: true,
    fragmentMatcher: new IntrospectionFragmentMatcher({
      introspectionQueryResultData: introspectionData,
    }),
    dataIdFromObject: result => {
      if (result.id && result.__typename) {
        // eslint-disable-line no-underscore-dangle
        return `${result.__typename}_${result.id}`; // eslint-disable-line no-underscore-dangle
      }
      return null;
    },
    networkInterface: networkInterfaceWithSubscriptions,
  });

  client.resetWebsocket = () => {
    if (wsClient.client) {
      // Close socket connection which will also unregister subscriptions on the server-side.
      wsClient.close(true);

import {IntrospectionFragmentMatcher} from 'apollo-client';

// TODO this is a short-term fix
// we need to set up something to query the server for the schema before ApolloClient initialization
// https://github.com/apollographql/apollo-client/issues/1555#issuecomment-295834774
const fm = new IntrospectionFragmentMatcher({
  introspectionQueryResultData: {
    __schema: {
      types: [
        {
          kind: 'INTERFACE',
          name: 'UserError',
          possibleTypes: [
            {name: 'GenericUserError'},
            {name: 'ValidationUserError'}
          ]
        },
        {
          kind: 'INTERFACE',
          name: 'Response',
          possibleTypes: [
            {name: 'CreateCommentResponse'},

uri: requestUri,
    });

  // Use persisted queries and GET requests in production.
  const finalNetworkInterface =
    isProduction && hasApiVersion
      ? addGetRequests(
          addPersistedQueries(apiVersion, queryMap, networkInterface),
        )
      : networkInterface;

  const apolloClient = new ApolloClient({
    reduxRootSelector: state => state.apollo,
    networkInterface: finalNetworkInterface,
    ssrMode: __SERVER__,
    fragmentMatcher: new IntrospectionFragmentMatcher({
      introspectionQueryResultData: introspectionData,
    }),
  });

  return apolloClient;
};

uri: requestUri,
    });

  // Use persisted queries and GET requests in production.
  const finalNetworkInterface =
    isProduction && hasApiVersion
      ? addGetRequests(
          addPersistedQueries(apiVersion, queryMap, networkInterface),
        )
      : networkInterface;

  const apolloClient = new ApolloClient({
    reduxRootSelector: state => state.apollo,
    networkInterface: finalNetworkInterface,
    ssrMode: __SERVER__,
    fragmentMatcher: new IntrospectionFragmentMatcher({
      introspectionQueryResultData: introspectionData,
    }),
  });

  return apolloClient;
};

if (!req.options.headers) {
      req.options.headers = {};
    }

    const token = await Auth.getToken();
    req.options.headers.authorization = token;
    next();
  },
}]);

const networkInterfaceWithSubscriptions = addGraphQLSubscriptions(
  networkInterface,
  wsClient,
);

const feedFragmentMatcher = new IntrospectionFragmentMatcher({
  introspectionQueryResultData: {
    __schema: {
      types: [
        {
          kind: 'INTERFACE',
          name: 'Feed',
          possibleTypes: [
            {
              name: 'GroupFeed',
            },
            {
              name: 'TripFeed',
            },
            {
              name: 'CommentFeed',
            },

connectionParams: () => {
          if (!AuthorizationMiddleware.token || AuthorizationMiddleware.token === '') {
            return {};
          }

          return {'player-token': AuthorizationMiddleware.token};
        },
        connectionCallback: (error => {
          if (error) {
            AuthorizationMiddleware.setToken('');
            window.location.href = '/';
          }
        })
      });

      const fragmentMatcher = new IntrospectionFragmentMatcher({
        introspectionQueryResultData: {
          __schema: {
            types: [
              {
                'kind': 'INTERFACE',
                'name': 'User',
                'possibleTypes': [
                  {'name': 'Player'},
                  {'name': 'Viewer'}
                ]
              },
            ],
          },
        }
      });