You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: client_auth_test.go
    path of file: ./repos/memphis/test
    
    the code of the file until where you have to start completion: // Copyright 2016-2019 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
    
func TestMultipleUserAuth(t *testing.T) {
	srv, opts := RunServerWithConfig("./configs/multi_user.conf")
	defer srv.Shutdown()

	if opts.Users == nil {
		t.Fatal("Expected a user array that is not nil")
	}
	if len(opts.Users) != 2 {
		t.Fatal("Expected a user array that had 2 users")
	}

	// Test first user
	url := fmt.Sprintf("nats://%s:%s@%s:%d/",
		opts.Users[0].Username,
		opts.Users[0].Password,
		opts.Host, opts.Port)

	nc, err := nats.Connect(url)
	if err != nil {
		t.Fatalf("Expected a successful connect, got %v\n", err)
	}
	defer nc.Close()

	if !nc.AuthRequired() {
		t.Fatal("Expected auth to be required for the server")
	}

	// Test second user
	url = fmt.Sprintf("nats://%s:%s@%s:%d/",
		opts.Users[1].Username,
		opts.Users[1].Password,
		opts.Host, opts.Port)

	nc, err = nats.Connect(url)
	if err != nil {
		t.Fatalf("Expected a successful connect, got %v\n", err)
	}
	defer nc.Close()
}