```ruby
require_relative 'spec_helper'

describe 'box' do
  it 'should have a root user' do
    expect(user 'root').to exist
  end

  it 'should have a vagrant user' do
    expect(user 'vagrant').to exist
  end

  it 'should not have a .vbox_version file' do
    expect(file '/home/vagrant/.vbox_version').to_not be_file
  end

  it 'should disable SELinux' do
    expect(selinux).to be_disabled
  end
end
```

Add test for slow DNS fix
user
```ruby
require_relative 'spec_helper'

describe 'box' do
  it 'should have a root user' do
    expect(user 'root').to exist
  end

  it 'should have a vagrant user' do
    expect(user 'vagrant').to exist
  end

  it 'should not have a .vbox_version file' do
    expect(file '/home/vagrant/.vbox_version').to_not be_file
  end

  it 'should disable SELinux' do
    expect(selinux).to be_disabled
  end

  vbox_string = command("dmesg | grep VirtualBox").stdout
  has_vbox = vbox_string.include? 'VirtualBox'
  it 'should have single-request-reopen on virtualbox', :if => has_vbox do
    if file('/redhat/release').content.scan(/(release 5) | (release 6)/)
      expect(file('/etc/resolv.conf').content).to match /single-request-reopen/
    end
  end
end
```
assistant