System.Xml.Xsl.XsltContext.ResolveFunction C# (CSharp) Method

        public abstract IXsltContextFunction ResolveFunction(string prefix, string name, XPathResultType[] ArgTypes);
        public abstract bool Whitespace { get; }

 public override void SetXsltContext(XsltContext context)
 {
     if (context == null)
     {
         throw XPathException.Create(SR.Xp_NoContext);
     }
     if (this.xsltContext != context)
     {
         xsltContext = context;
         foreach (Query argument in _args)
         {
             argument.SetXsltContext(context);
         }
         XPathResultType[] argTypes = new XPathResultType[_args.Count];
         for (int i = 0; i < _args.Count; i++)
         {
             argTypes[i] = _args[i].StaticType;
         }
         _function = xsltContext.ResolveFunction(prefix, name, argTypes);
         // KB article allows to return null, see http://support.microsoft.com/?kbid=324462#6
         if (_function == null)
         {
             throw XPathException.Create(SR.Xp_UndefFunc, QName);
         }
     }
 }