Compile and execute a stateful T4 template using Mono.TextTemplating

var input =
    "<#@ template language=\"C#\" debug=\"true\" #>" +
    "<#+ static int num; #>" +
    "<#= num++ #>";
var generator = new TemplateGenerator();
var compiled = generator.CompileTemplate(input);
Debug.Assert(Equals(compiled.Process(), "0"));
Debug.Assert(Equals(compiled.Process(), "1"));
Debug.Assert(Equals(compiled.Process(), "2"));

Mono.TextTemplating