public void NavbarWithButton()
{
var output = new StringBuilder();
var writer = new StringBuilderWriter(output);
using (var navbar = new Navbar(writer))
{
writer.Write(navbar.Button("Sign In"));
}
Assert.AreEqual("<nav class=\"navbar navbar-default\" role=\"navigation\"><div class=\"container\">" +
"<button class=\"btn btn-default navbar-btn\">Sign In</button>" +
"</div></nav>", output.ToString());
}