it 'instructor should not be able to impersonate an admin user with their real name' do
      allow(User).to receive(:find_by).with(name: admin.name).and_return(admin)
      allow(instructor).to receive(:can_impersonate?).with(admin).and_return(false)
      request.env['HTTP_REFERER'] = 'http://www.example.com'
      @params = { user: { name: admin.name } }