code: function newClientStub() {
      // First create the appropriate TLS certs with dgraph cert:
      //     $ dgraph cert
      //     $ dgraph cert -n localhost
      //     $ dgraph cert -c user
      const rootCaCert = fs.readFileSync(path.join(__dirname, 'tls', 'ca.crt'));
      const clientCertKey = fs.readFileSync(path.join(__dirname, 'tls', 'client.user.key'));
      const clientCert = fs.readFileSync(path.join(__dirname, 'tls', 'client.user.crt'));
      return new dgraph.DgraphClientStub(
          "localhost:9080",
          grpc.credentials.createSsl(rootCaCert, clientCertKey, clientCert));
  }
docs: Create a client stub.