public void CommentParser()
{
var result = grammar.Comment(Source("<!-- hello world -->"));
Assert.IsNotNull(result);
Assert.AreEqual(" hello world ", result.Value.Text);
var result2 = grammar.Comment(Source("<!-- hello-world -->"));
Assert.IsNotNull(result2);
Assert.AreEqual(" hello-world ", result2.Value.Text);
var result3 = grammar.Comment(Source("<!-- hello--world -->"));
Assert.IsNull(result3);
}