System.Xml.DocumentXPathNavigator.MoveToFirst C# (CSharp) Method

        public override bool MoveToFirst() {
            if (source.NodeType == XmlNodeType.Attribute) {
                return false;
            }
            XmlNode parent = ParentNode(source);
            if (parent == null) {
                return false;
            }
            XmlNode sibling = FirstChild(parent);
            Debug.Assert(sibling != null);
            while (!IsValidChild(parent, sibling)) {
                sibling = NextSibling(sibling);
                if (sibling == null) {
                    return false;
                }
            }
            source = sibling;
            return true;
        }