// Read all the text from the xml file.
string xml = File.ReadAllText("file.xml");

// Create the class info and parse the xml text.
IEnumerable<Class> classInfo = XmlParser.Parse(xml);

// Since this is for .net 6 and c# 10, this is a new way to instance a class.
// Pass the info to the classWriter.
ClassWriter classWriter = new(classInfo);

// Then create a writer with the path you want to save the new csharp file.
string filePath = "C:\\ExportCSharpClass\\file.cs";
StreamWriter writer = new(filePath);

// Enable autoflush to ensure save all the text into de file.
// First you have to write the Header, wich is the 3 using statements you need
// And a custom namespace.
writer.AutoFlush = true;
classWriter.Header(writer, "Maplecodex2.Items");

// Second you write the body.
classWriter.Write(writer);

// And finally the footer, this is for the close brackets missing.
classWriter.Footer(writer);