namespace System.Xml.XPath { public abstract class XPathExpression { public abstract string Expression { get; } public abstract XPathResultType ReturnType { get; } public abstract void AddSort(object expr, IComparer comparer); public abstract void AddSort(object expr, XmlSortOrder order, XmlCaseOrder caseOrder, string lang, XmlDataType dataType); public abstract XPathExpression Clone(); public static XPathExpression Compile(string xpath); public static XPathExpression Compile(string xpath, IXmlNamespaceResolver nsResolver); public abstract void SetContext(IXmlNamespaceResolver nsResolver); public abstract void SetContext(XmlNamespaceManager nsManager); } }