How to use the apollo-link-http-common.selectURI function in apollo-link-http-common

return new ApolloLink(operation => {
    const uri = selectURI(operation, fetchUri)
    const context = operation.getContext()

    // Apollo Engine client awareness:
    // https://apollographql.com/docs/platform/client-awareness

    const {
      // From Apollo Client config.
      clientAwareness: { name, version } = {},
      headers
    } = context

    const contextConfig = {
      http: context.http,
      options: context.fetchOptions,
      credentials: context.credentials,
      headers: {

return new ApolloLink(operation => {
    let chosenURI = selectURI(operation, uri);

    const context = operation.getContext();

    // `apollographql-client-*` headers are automatically set if a
    // `clientAwareness` object is found in the context. These headers are
    // set first, followed by the rest of the headers pulled from
    // `context.headers`. If desired, `apollographql-client-*` headers set by
    // the `clientAwareness` object can be overridden by
    // `apollographql-client-*` headers set in `context.headers`.
    const clientAwarenessHeaders = {};
    if (context.clientAwareness) {
      const { name, version } = context.clientAwareness;
      if (name) {
        clientAwarenessHeaders['apollographql-client-name'] = name;
      }
      if (version) {

((operation: Operation) => {
        const context = operation.getContext();

        const contextConfig = {
          http: context.http,
          options: context.fetchOptions,
          credentials: context.credentials,
          headers: context.headers,
        };

        //may throw error if config not serializable
        return selectURI(operation, uri) + JSON.stringify(contextConfig);
      });

const batchHandler = (operations: Operation[]) => {
      const chosenURI = selectURI(operations[0], uri);

      const context = operations[0].getContext();

      const clientAwarenessHeaders = {};
      if (context.clientAwareness) {
        const { name, version } = context.clientAwareness;
        if (name) {
          clientAwarenessHeaders['apollographql-client-name'] = name;
        }
        if (version) {
          clientAwarenessHeaders['apollographql-client-version'] = version;
        }
      }

      const contextConfig = {
        http: context.http,