System.Xml.XmlTextWriter.FindPrefix C# (CSharp) Method

        string FindPrefix(string ns) {
            for (int i = nsTop; i >= 0; i--) {
                if (nsStack[i].ns == ns) {
                    if (LookupNamespace(nsStack[i].prefix) == i) {
                        return nsStack[i].prefix;
                    }
                }
            }
            return null;
        }