Html/Css queries to Xpath helper methods in c#

html_xpath.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CssPath
{
    public static class By
    {
        public const string AnchorTag = "a";
        public const string AnyNode = "*";

        public enum Comparison
        {
            Presence,
            Equality,
            Contains,
            StartsWith,
            EndsWith,
        }

        public static string XPath(string xpath)
        {
            return xpath;
        }

        public static string Tag(string tagName)
        {
            return string.Format(@"//{0}", tagName);
        }

        public static string Id(string id)
        {
            return XPath(Comparison.Equality, "id", id);
        }

        public static string ClassName(string name, Comparison type = Comparison.Equality)
        {
            return XPath(type, "class", name);
        }

        public static string Link(string linkText, Comparison comparisonType = Comparison.Equality)
        {
            return XPath(comparisonType ,"href", linkText, AnchorTag);
        }

        public static string PartialLink(string linkText)
        {
            return Link(linkText, Comparison.Contains);
        }

        public static string Attribute(string attribute, string name, Comparison comparisonType = Comparison.Equality, string node = null)
        {
            return XPath(comparisonType, attribute, name, node);
        }

        private static string XPath(Comparison compareBy, string attribute, string name = "", string node = null)
        {
            switch(compareBy)
            {
                case Comparison.Equality:
                    return string.Format(@"//{0}[@{1}]", node ?? AnyNode);

                case Comparison.Presence:
                    return string.Format(@"//{0}[@{1}=""{2}""]", node ?? AnyNode, attribute, name);

                case Comparison.Contains:
                    return XpathFunction(node, "contains", attribute, name);

                case Comparison.StartsWith:
                    return XpathFunction(node, "starts-with", attribute, name);

                case Comparison.EndsWith:
                    return XpathFunction(node, "ends-with", attribute, name);

                default:
                    return string.Empty;
            }
        }

        private static string XpathFunction(string node, string func, string attr, string name)
        {
            return string.Format(@"//{0}[{1}(@{2}=""{3}"")]", node ?? AnyNode, func, attr, name);
        }
    }
}