private void DefineTypeAndDefaultConstructor(TypeBuilder parentTypeBuilder)
        {
            Type = parentTypeBuilder.DefineNestedType(
                $"{parentTypeBuilder.Name}_AsyncStateMachine",
                TypeAttributes.Class |
                TypeAttributes.NestedPrivate |
                TypeAttributes.Sealed |
                TypeAttributes.AutoClass |
                TypeAttributes.AnsiClass |
                TypeAttributes.BeforeFieldInit);

            Type.AddInterfaceImplementation(typeof(IAsyncStateMachine));

            Constructor = Type.DefineDefaultConstructor(MethodAttributes.Public);
        }